Background: Epidemiological data are limited regarding clinical characteristic of adverse drug reactions (ADRs) in India. Aim: The aim was to assess ADRs with reference to the causative drugs, seriousness and their other clinical characteristics in Indian tertiary care teaching hospital. Methods: A spontaneous reporting based ADR monitoring study was conducted over a period of 2 years. The World Health Organization (WHO) definition of an ADR and its seriousness was adopted. The organ system involvement was labeled by WHO-ADR terminology. ADRs were analyzed for causality by Naranjo's algorithm, preventability by modified Schumock and Thornton's criteria and types of reactions by Rawlins and Thompson classification. Subgroup analysis was performed between serious and non-serious reactions. Results: Of the total of 135 reactions reported 111 reactions from 97 patients were included for analysis. The incidences of overall and serious ADRs were 0.25 and 0.06 per 1000 patients, respectively. The most commonly implicated organ systems were skin and appendages (52.25%). The major causative drug classes were antimicrobials (40.28%), central nervous system (23.61%) and autacoids (15.97%). About twothirds of the reactions (65.77%) were classified as probable and one-tenth (8.10%) as preventable. The factors significantly associated with serious reactions were age group 40-60 years (odds ratio [OR]: 5.51), parenteral drugs (OR: 2.96), central and peripheral nervous system disorders (OR: 5.06), body as a whole -general disorders (OR: 9.05) and acute onset reactions (OR: 52.62). Conclusion: Antimicrobials are common causative agents. Cohort study is recommended to confirm the risk factors of serious ADRs in Indian population.