Objective: To study the prescribing pattern of drugs in patients attending medicine outpatient department and to evaluate the drug used for rationality with the help of W.H.O core drug prescribing indicators. Methods: This prospective study was carried out in medicine outpatient department of a tertiary care teaching hospital for two months. The data was collected from patients of all age and from either sex after taking written informed consent, in a proforma which included the patient__ampersandsignlsquo;s demographic details and the drugs prescribed. Data were analyzed for drug use pattern. Results: Total 450 prescriptions (2143 drugs) were analyzed. The analysis of pattern of drug use revealed that NSAIDS, vitamins, and antibiotics were the most frequently prescribed drug groups. Amongst antibiotics penicillin group was most commonly prescribed group. Amoxicillin and clavulanic acid combination was found be the most commonly prescribed antibiotic. FDCs in the form of multivitamin preparations were found to be highest in number. FDCs accounted for 36.73% of medicine formulations prescribed in our study. WHO core drug prescribing indicators show polypharmacy, and less drug prescribing by generic names. Only 35.09% of drugs were prescribed from the WHO Essential drug list. Antibiotics and injections were prescribed in 41.55% and 8.2% of encounters respectively. Conclusion: There is a need to educate the prescriber on rational drug therapy for benefits and safety of the patients. There is also need to conduct similar studies at frequent intervals of time, which would reflect the changing pattern of drugs in medicine out-patients.