Introduction:A cross-sectional study was conducted among health care workers (Nurses) at a tertiary care hospital in Trivandrum, Kerala to study the proportion of needle stick injury and associated factors. A semi structured questionnaire was used to collect data from the study participants at their work place. Participants were asked to recall needle stick injuries (NSIs) in the preceding 6 months and definition of needle stick injury was formulated. Factors such as work experience, type of procedure, action taken following injury etc were also studied. Results: The prevalence of NSIs was 94(47%). Mean age of 200 participants was 32.8 years (+ 6.8), all were female. Emergency department accounted for highest (62.8%) of NSIs. & it was maximum (42.6%) during injection procedure. Heavy work load (37.2%) followed by inattention (32%) were prime causes. Following injury 34% of nurses washed injury site with soap & water and applied antiseptics as well. usage of personal protective equipment(PPE) was 84%. Prime causes for not using PPEs were lack of supply and inappropriate size of gloves respectively. Usage of PPEs were found to be significant in preventing NSIs. Conclusion: Prevalence of NSI is high and measure for safety concern. There is urgent need of close monitoring and implementation of uniform NSIs programme like safe practices, safe disposal of sharps, mandatory reporting of needle stick injury at work station. Provision of post exposure prophylaxis following NSIs. Limitation: Small sample size, purposive-sampling and impact of information broacher regarding NSIs could not be accessed.