Pharmacovigilance heavily focuses on adverse drug reactions, or ADRs, and SADR which are defined as any response to a drug which is noxious and unintended, including lack of efficacy, which occurs at doses normally used for the prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function. Medication errors such as overdose, and misuse and abuse of a drug, are also of interest because they may result in an ADR. (Gupta, 2001). Metformin an oral antidiabetic drug in the biguanide class. It is the first line drug of choice for the treatment of type-2 diabetes. Its main use is in overweight patients, particular those are normal kidney function. In the present study 133 cases were studied with the help of Argus safety data base in which 188 adverse drug reactions occurred. Out of 188 adverse drug reactions 100 were found in Females and 88 ADR’s were occurred in Males.