ABSTRACTObjectives: Adverse drug reaction (ADR) is an important cause of morbidity, mortality, and prolonged hospitalization. The objective of this study is tomeasure the incidence, types, and nature of ADR in a tertiary care hospital located in Silchar, Assam.Methods: A retrospective noninterventional analysis of all ADRs reported by ADR Monitoring Centre, Department of Pharmacology, Silchar MedicalCollege, from March 2014 to February 2015 was performed. A total of 162 predesigned forms were used for collection of data. All forms were dulychecked for completeness, if not, they were rejected.Results: A total of 162 forms were assessed of which 96 (59%) were females and 66 (41%) were males. The distribution of ADRs in different age groupswere found to be 3 (1.85%) in 0-15 years, 71 (43.82%) in 16-30 years, 65 (40.12%) in 31-45 years, 8 (4.93%) in 46-60 years, and 15 (9.25%) in agegroup >60 years. 150 (92.6%) of the ADRs were serious and 12 (7.4%) were not serious. As per the World Health Organization causality assessmentscale, 120 (74.07%) were probable and 42 (25.92%) were possible. The most common ADR was anaphylactic reaction (AR) in 69 (42.59%) patients.The drugs which commonly caused ADR were iron sucrose infusions, nevirapine, cephalosporins, antiprotozoals, nonsteroidal anti-inflammatorydrugs, and quinolones followed by others.Conclusion: The majority of ADRs were probable. The most common ADR was AR caused by iron sucrose infusion. Different drugs caused differentADRs. ADRs thereby increase morbidity and mortality in patients as well as socioeconomic burden.Keywords: Adverse drug reaction, Anaphylactic reaction, Iron sucrose infusion, Noninterventional, Retrospective analysis.