Needle stick injury (NSIs) is the main transmission source of blood borne infection among health care workers all over the world. Nurses are at high risk of needle stick injury with acquisition of blood-borne infection by pathogens while performing their clinical activities in the hospitals. Thus, this study aim was to assess the knowledge and practice of nurses regarding needle stick injury in Public Hospitals Lahore, Pakistan. Cross sectional study technique was used in the current study. Self-administered questionnaire was distributed among 186 nurses through convenient random sampling. Descriptive analysis was used to analyze the data. Finding of this study shows that most of the nurses have good knowledge about needle stick injury but application of the knowledge in their practical work was poor. The study recommends that the health education program for needle stick injury and prevention measure should be introduced to all the nurses intensively and encourages them to apply during their daily practice.