diff --git a/backend/pmr_api.py b/backend/pmr_api.py
index 4ddbcad..55ab24e 100644
--- a/backend/pmr_api.py
+++ b/backend/pmr_api.py
@@ -650,3 +650,134 @@ def get_patient_history(cus_code):
     except Exception as e:
         logging.error(f"환자 이전 처방 조회 오류: {e}")
         return jsonify({'success': False, 'error': str(e)}), 500
+
+
+# ─────────────────────────────────────────────────────────────
+# API: 환자 OTC 구매 이력
+# ─────────────────────────────────────────────────────────────
+@pmr_bp.route('/api/patient/<cus_code>/otc', methods=['GET'])
+def get_patient_otc_history(cus_code):
+    """
+    환자 OTC (일반의약품) 구매 이력 조회
+    
+    Args:
+        cus_code: 환자 고유코드 (CusCode = SL_CD_custom)
+        
+    Query Params:
+        - limit: 최대 조회 건수 (기본 20, 최대 100)
+    """
+    try:
+        limit = min(int(request.args.get('limit', 20)), 100)
+        
+        conn = get_mssql_connection('PM_PRES')
+        cursor = conn.cursor()
+        
+        # OTC 거래 목록 조회 (PRESERIAL = 'V' = OTC 판매)
+        cursor.execute("""
+            SELECT 
+                m.SL_NO_order,
+                m.SL_DT_appl,
+                m.InsertTime,
+                m.SL_MY_sale,
+                m.SL_NM_custom
+            FROM SALE_MAIN m
+            WHERE m.SL_CD_custom = ?
+              AND m.PRESERIAL = 'V'
+            ORDER BY m.InsertTime DESC
+        """, (cus_code,))
+        
+        # 먼저 거래 목록 수집
+        orders = []
+        for row in cursor.fetchall():
+            orders.append({
+                'order_no': row.SL_NO_order,
+                'date': row.SL_DT_appl,
+                'datetime': row.InsertTime.strftime('%Y-%m-%d %H:%M') if row.InsertTime else '',
+                'amount': int(row.SL_MY_sale or 0),
+                'customer_name': row.SL_NM_custom or ''
+            })
+        
+        # 최근 limit개만
+        orders = orders[:limit]
+        
+        if not orders:
+            conn.close()
+            return jsonify({
+                'success': True,
+                'cus_code': cus_code,
+                'count': 0,
+                'purchases': []
+            })
+        
+        # 각 거래의 품목 조회
+        purchases = []
+        for order in orders:
+            cursor.execute("""
+                SELECT 
+                    s.DrugCode,
+                    g.GoodsName,
+                    s.SL_NM_item,
+                    s.SL_TOTAL_PRICE,
+                    mc.PRINT_TYPE
+                FROM SALE_SUB s
+                LEFT JOIN PM_DRUG.dbo.CD_GOODS g ON s.DrugCode = g.DrugCode
+                LEFT JOIN PM_DRUG.dbo.CD_MC mc ON s.DrugCode = mc.DRUGCODE
+                WHERE s.SL_NO_order = ?
+                ORDER BY s.DrugCode
+            """, (order['order_no'],))
+            
+            items = []
+            for item_row in cursor.fetchall():
+                items.append({
+                    'drug_code': item_row.DrugCode or '',
+                    'name': item_row.GoodsName or item_row.DrugCode or '',
+                    'quantity': int(item_row.SL_NM_item or 0),
+                    'price': int(item_row.SL_TOTAL_PRICE or 0),
+                    'category': item_row.PRINT_TYPE or ''
+                })
+            
+            purchases.append({
+                **order,
+                'items': items,
+                'item_count': len(items)
+            })
+        
+        conn.close()
+        
+        # 통계 계산
+        total_amount = sum(p['amount'] for p in purchases)
+        total_visits = len(purchases)
+        
+        # 자주 구매하는 품목 집계
+        item_freq = {}
+        for p in purchases:
+            for item in p['items']:
+                key = item['drug_code']
+                if key not in item_freq:
+                    item_freq[key] = {
+                        'name': item['name'],
+                        'category': item['category'],
+                        'count': 0,
+                        'total_qty': 0
+                    }
+                item_freq[key]['count'] += 1
+                item_freq[key]['total_qty'] += item['quantity']
+        
+        # 빈도순 정렬
+        frequent_items = sorted(item_freq.values(), key=lambda x: x['count'], reverse=True)[:10]
+        
+        return jsonify({
+            'success': True,
+            'cus_code': cus_code,
+            'count': len(purchases),
+            'summary': {
+                'total_visits': total_visits,
+                'total_amount': total_amount,
+                'frequent_items': frequent_items
+            },
+            'purchases': purchases
+        })
+        
+    except Exception as e:
+        logging.error(f"환자 OTC 구매 이력 조회 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
diff --git a/backend/templates/pmr.html b/backend/templates/pmr.html
index 9480d4b..871139a 100644
--- a/backend/templates/pmr.html
+++ b/backend/templates/pmr.html
@@ -150,6 +150,125 @@
             color: #92400e !important;
             margin-left: 5px;
         }
+        .detail-header .rx-info .otc-badge {
+            background: #dbeafe !important;
+            color: #1e40af !important;
+            cursor: pointer;
+            transition: all 0.2s;
+        }
+        .detail-header .rx-info .otc-badge:hover {
+            background: #bfdbfe !important;
+            transform: scale(1.05);
+        }
+        
+        /* OTC 모달 */
+        .otc-modal {
+            display: none;
+            position: fixed;
+            top: 0; left: 0; right: 0; bottom: 0;
+            background: rgba(0,0,0,0.6);
+            z-index: 1000;
+            overflow-y: auto;
+        }
+        .otc-modal-content {
+            max-width: 600px;
+            margin: 40px auto;
+            background: #fff;
+            border-radius: 16px;
+            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
+            overflow: hidden;
+        }
+        .otc-modal-header {
+            background: linear-gradient(135deg, #3b82f6, #60a5fa);
+            color: #fff;
+            padding: 20px 25px;
+            display: flex;
+            justify-content: space-between;
+            align-items: center;
+        }
+        .otc-modal-header h3 { margin: 0; font-size: 1.2rem; }
+        .otc-modal-close {
+            background: none;
+            border: none;
+            color: #fff;
+            font-size: 1.5rem;
+            cursor: pointer;
+            opacity: 0.8;
+        }
+        .otc-modal-close:hover { opacity: 1; }
+        .otc-summary {
+            display: flex;
+            gap: 20px;
+            padding: 15px 25px;
+            background: #f8fafc;
+            border-bottom: 1px solid #e2e8f0;
+        }
+        .otc-summary-item {
+            text-align: center;
+        }
+        .otc-summary-item .num {
+            font-size: 1.5rem;
+            font-weight: 700;
+            color: #1e40af;
+        }
+        .otc-summary-item .label {
+            font-size: 0.75rem;
+            color: #64748b;
+        }
+        .otc-frequent {
+            padding: 15px 25px;
+            border-bottom: 1px solid #e2e8f0;
+        }
+        .otc-frequent h4 {
+            margin: 0 0 10px 0;
+            font-size: 0.9rem;
+            color: #475569;
+        }
+        .otc-frequent-list {
+            display: flex;
+            flex-wrap: wrap;
+            gap: 8px;
+        }
+        .otc-frequent-item {
+            background: #eff6ff;
+            color: #1e40af;
+            padding: 4px 12px;
+            border-radius: 20px;
+            font-size: 0.8rem;
+        }
+        .otc-purchases {
+            max-height: 300px;
+            overflow-y: auto;
+            padding: 15px 25px;
+        }
+        .otc-purchase {
+            border: 1px solid #e2e8f0;
+            border-radius: 10px;
+            margin-bottom: 12px;
+            overflow: hidden;
+        }
+        .otc-purchase-header {
+            background: #f1f5f9;
+            padding: 10px 15px;
+            display: flex;
+            justify-content: space-between;
+            font-size: 0.85rem;
+        }
+        .otc-purchase-header .date { color: #475569; font-weight: 600; }
+        .otc-purchase-header .amount { color: #1e40af; font-weight: 600; }
+        .otc-purchase-items {
+            padding: 10px 15px;
+        }
+        .otc-purchase-item {
+            display: flex;
+            justify-content: space-between;
+            padding: 5px 0;
+            font-size: 0.85rem;
+            border-bottom: 1px solid #f1f5f9;
+        }
+        .otc-purchase-item:last-child { border-bottom: none; }
+        .otc-purchase-item .name { color: #1e293b; }
+        .otc-purchase-item .qty { color: #64748b; }
         
         /* 약품 목록 */
         .medication-list {
@@ -443,6 +562,19 @@
                 <button class="btn btn-primary" onclick="printLabels()">🖨️ 라벨 인쇄</button>
             </div>
             
+            <!-- OTC 구매 이력 모달 -->
+            <div class="otc-modal" id="otcModal">
+                <div class="otc-modal-content">
+                    <div class="otc-modal-header">
+                        <h3>💊 OTC 구매 이력</h3>
+                        <button class="otc-modal-close" onclick="closeOtcModal()">×</button>
+                    </div>
+                    <div class="otc-summary" id="otcSummary"></div>
+                    <div class="otc-frequent" id="otcFrequent"></div>
+                    <div class="otc-purchases" id="otcPurchases"></div>
+                </div>
+            </div>
+            
             <!-- 미리보기 모달 -->
             <div id="previewModal" style="display:none;position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,0.7);z-index:1000;overflow-y:auto;">
                 <div style="max-width:400px;margin:50px auto;background:#fff;border-radius:12px;padding:20px;">
@@ -480,6 +612,7 @@
         let historyData = [];
         let historyIndex = 0;
         let compareMode = false;
+        let otcData = null;
         
         // HTML 이스케이프
         function escapeHtml(text) {
@@ -644,6 +777,7 @@
                     currentPatientCode = data.patient.code;
                     if (currentPatientCode) {
                         loadPatientHistory(currentPatientCode, prescriptionId);
+                        checkOtcHistory(currentPatientCode);
                     }
                 }
             } catch (err) {
@@ -917,6 +1051,89 @@
             `;
         }
         
+        // OTC 구매 이력 체크
+        async function checkOtcHistory(cusCode) {
+            try {
+                const res = await fetch(`/pmr/api/patient/${cusCode}/otc?limit=20`);
+                const data = await res.json();
+                
+                if (data.success && data.count > 0) {
+                    otcData = data;
+                    // OTC 뱃지 추가 (질병 뱃지 앞에)
+                    const rxInfo = document.getElementById('rxInfo');
+                    const otcBadge = `<span class="otc-badge" onclick="showOtcModal()">💊 OTC ${data.count}건</span>`;
+                    rxInfo.innerHTML = otcBadge + rxInfo.innerHTML;
+                } else {
+                    otcData = null;
+                }
+            } catch (err) {
+                console.error('OTC check error:', err);
+                otcData = null;
+            }
+        }
+        
+        // OTC 모달 표시
+        function showOtcModal() {
+            if (!otcData) return;
+            
+            const modal = document.getElementById('otcModal');
+            const summary = document.getElementById('otcSummary');
+            const frequent = document.getElementById('otcFrequent');
+            const purchases = document.getElementById('otcPurchases');
+            
+            // 요약
+            summary.innerHTML = `
+                <div class="otc-summary-item">
+                    <div class="num">${otcData.summary.total_visits}</div>
+                    <div class="label">방문</div>
+                </div>
+                <div class="otc-summary-item">
+                    <div class="num">${(otcData.summary.total_amount / 10000).toFixed(1)}만</div>
+                    <div class="label">총 구매액</div>
+                </div>
+            `;
+            
+            // 자주 구매하는 품목
+            if (otcData.summary.frequent_items && otcData.summary.frequent_items.length > 0) {
+                frequent.innerHTML = `
+                    <h4>🔥 자주 구매하는 품목</h4>
+                    <div class="otc-frequent-list">
+                        ${otcData.summary.frequent_items.map(item => 
+                            `<span class="otc-frequent-item">${item.name} (${item.count}회)</span>`
+                        ).join('')}
+                    </div>
+                `;
+                frequent.style.display = 'block';
+            } else {
+                frequent.style.display = 'none';
+            }
+            
+            // 구매 이력
+            purchases.innerHTML = otcData.purchases.map(p => `
+                <div class="otc-purchase">
+                    <div class="otc-purchase-header">
+                        <span class="date">📅 ${p.date?.replace(/(\d{4})(\d{2})(\d{2})/, '$1-$2-$3') || p.datetime}</span>
+                        <span class="amount">${p.amount.toLocaleString()}원</span>
+                    </div>
+                    <div class="otc-purchase-items">
+                        ${p.items.map(item => `
+                            <div class="otc-purchase-item">
+                                <span class="name">${item.name}</span>
+                                <span class="qty">${item.quantity}개 / ${item.price.toLocaleString()}원</span>
+                            </div>
+                        `).join('')}
+                    </div>
+                </div>
+            `).join('');
+            
+            modal.style.display = 'block';
+        }
+        
+        // OTC 모달 닫기
+        function closeOtcModal() {
+            document.getElementById('otcModal').style.display = 'none';
+        }
+        
         // 상세 초기화
         function clearDetail() {
             document.getElementById('detailHeader').style.display = 'none';
@@ -925,6 +1142,7 @@
             document.getElementById('compareToggle').style.display = 'none';
             document.getElementById('compareMode').checked = false;
             document.getElementById('compareLegend').style.display = 'none';
+            document.getElementById('otcModal').style.display = 'none';
             document.getElementById('medicationList').innerHTML = `
                 <div class="empty-state">
                     <div class="icon">👈</div>
@@ -937,6 +1155,7 @@
             historyData = [];
             historyIndex = 0;
             compareMode = false;
+            otcData = null;
         }
         
         // 전체 선택 토글