OBJECTIVE: To investigate the occurrence of ADR induced by over-the-counter (OTC) drug in order to guide the rational use of drugs. METHODS: 45 cases of ADR induced by OTC drug were analyzed retrospectively in terms of patient’s general information, allergic history, allergenic drugs, reason for drug use, route of administration, incubation period, days of hospitalization, clinical manifestation, treatment, outcome, etc. RESULTS: Among 45 patients, there were 14 male and 31 female. The patients were mainly 20-30 year-old (31.1%). Three patients had previous history of allergy (6.7%). Most ADR were induced by oral drugs (82.2%). Reasons for drug use were mainly disease of respiratory system (23 cases, 51.1%). The results of causality assessment were positive in 3 patients (6.7%), probable in 35 (n=77.8%), and possible in 7 patients (15.6%). ADR were mainly induced by non-steroidal anti-inflammatory drugs (NSAIDs, 57.8%), Chinese patent medicine (20.0%), drugs for external use (17.8%). The clinical manifestations mainly included exanthematous drug eruption (33.3%), erythama multiforme drug eruption (24.4%), urticarial drug eruption (13.3%). CONCLUSIONS: NSAIDs are the main allergenic drugs, and ADR induced by OTC traditional Chinese medicine can not be ignored. To improve medical knowledge and skills of the public and the scientific use of OTC drug are beneficial to improve the clinical treatment level.