Background: Adverse Drug Reactions (ADR) are common in hospitalized patients. Nursing staff spends most time in patient care placing them at a key it position to recognize ADRs at the earliest. However, ADR reporting practices among nurses is very poor. We conducted this study to identify the factors affecting knowledge and attitude of nurses in a teaching hospital towards ADR reporting.Methods: A pre-tested and validated questionnaire was used. Correct responses in the knowledge section were awarded one mark and incorrect responses were given zero. Based on responses to attitude questions on a 5-point Likert scale, best attitude was scored five and least preferred attitude was given one point. Total knowledge and attitude scores were analyzed with regards to age, gender, educational qualification, average weekly working hours, total working experience in years and past experience with ADRs and ADR reporting. Knowledge scores were also correlated with attitude scores.Results: Knowledge level was poor with 48.29±23.85% average score while attitude of the respondents was reasonable with 65.69±10.05% average scores. The knowledge scores and attitude scores of BSc degree holders was higher than GNMs and ANMs (p<0.001). Those who had independently identified an ADR had higher knowledge scores (p<0.01) and more positive attitude (p<0.001). Attitude scores also had a significantly strong correlation with knowledge level of the respondents (r=0.72).Conclusions: Knowledge about ADR reporting is the most important factor determining the attitude towards ADR reporting. Increasing awareness would be pivotal in changing attitude and thus, improving reporting rates.