Background: Needle stick injuries are serious occupational hazards in the transmission of a variety of bloodborne diseases, more than twenty pathogens can be transmitted through NSI including hepatitis B virus, hepatitis C virus, and human immunodeficiency virus (AIDS) among healthcare workers. Objectives: Assess the knowledge, attitude and practice of health care workers towards needle stick injuries. Determine the prevalence of needle stick injuries among healthcare workers and its predisposing factors.  Methods: Cross-sectional descriptive study, a convenient sample of 260 health care workers was selected from Baghdad Teaching hospital and Ghazy Al Hariri hospital in Baghdad, Iraq. Data were collected by an anonymous questionnaire from January to June 2020. The collected data were analyzed by using statistical package for the social sciences (SPSS version 23). Results Prevalence of NSIs among HCWs was found to be 53.8%, which was higher in nurses (29.3%) and laboratory technicians (28.5%) followed by surgeon doctors (15.7%), assistant surgeons (13.6%) and dentists (12.9%) .The highest number of needle stick injuries occurred by recapping of needles (41.4%) followed by during drug administration (27.9%), from hand to hand  (10.7%) and during blood drawing (7.9%). A proportion of (64.5%) of  health care workers whom sustained needle stick injury had reported their Injury. Doctors scored better than others regarding mean scores of knowledge, attitude and practice. There was a highly significant association among knowledge, attitude and practice scores of the HCWs (P<0.001). A considerable percentage of the participants (80.2%) were completely immunized against HBV. Conclusions: The study showed a high prevalence of NSIs among health care workers. The score of knowledge was high, moreover acceptable responses were obtained in most attitude and practice statements, except for recapping of needles statements.