OBJECTIVE: To analyze the contribution of adverse drug events (ADEs) to the overall number of visits to the medical emergency and to determine the proportion of events leading to hospital admissions. PATIENTS AND METHODS: All visits to the medical emergency were recorded in a prospective, non-interventional design study over a period of 8 months. The ADEs were divided into 5 categories: adverse drug reactions (ADRs), drug interactions, patient non-compliance, physician non-compliance, and drug overdose. The cases were then followed-up to assess the prorportion of ADEs lead to hospitaliztion. RESULTS: A total of 4764 patients were included in the study. 5.9% of all visits were considered to be drug-related. The highest percentage of ADEs was observed in the age group less than 20 and more than 80 years. ADRs accounted for 45% of all ADEs, followed by patient non-compliance (28%). Patient and physician non-compliance were the main causes of drug-related hospital admissions. 52% of all ADE-related visits and 55% of ADE-related admissions were considered to be preventable. Non-steroidal antiinflammatory agents, oral hypoglycemics and antitubercular drugs were responsible for 37% of all ADRs. Non-compliance was mainly seen in hypertensives, asthmatics and epileptics. CONCLUSION: ADEs account for a sizable proportion of all visits to a medical emergency unit and some are serious enough to require hospitaliztion. A large number of ADE-related visits and admissions are preventable which highlights the importance of public education on the proper use of drugs, and also the need for regulation of the practice of unregistered medical practitioners in developing countries.