Needle Stick Injury (NSI) is a percutaneous wound set by a needle point, other sharp instruments or objects which is a major risk factor to transmit blood-borne diseases among health care professionals. Present study was done to assess NSI as a health hazard in regard to their knowledge & practice & to find out the co-relation between knowledge & practice among 100 health care workers of Private Hospitals, Pokhara, Nepal. Data was collected by structured questionnaire. Study result revealed that majority of health care workers were females (93%) with mean age of 22.66 years (±3.1). Forty two percent had wrong concept about the meaning of NSI. There were only 35% of workers who dispose the sharps in cardboard box where as 65% used wrong place. Only 22% had a proper practice of disposal of sharp box when it is 3/4th full. While finding a used needle on the floor after closing the box with sharp only 38% use a new box which is the correct means. Seventy nine percent of workers expressed that, they never received any training in the prevention &/ or treatment of NSI. There was a positive correlation between knowledge & practice scores (p= 0.004). As it denotes that poor knowledge leads to poor practice, thus study concludes that poor knowledge and practice can be the key causes to get NSI as a major health hazards among health care professionals.