Objective: This study was carried out to determine the needlestick injuries (NSI) of the operating room nurses with penetrating and sharp tools, the causes of the injury and the precautions taken to prevent the injury. Methods: A descriptive and cross-sectional study was conducted with the participation of 463 volunteer nurses from 27 different hospitals in Istanbul, Turkey. After obtaining the ethics committee, institutions and volunteer permissions of the study, the data were collected with two data collection forms formed in line with the literature knowledge and expert opinions. The data were analyzed using IBM SPSS 22.0 program and p<0.05 was significance value. Results: Participants were 18-61 years old, (mean: 35.9±0.84), 63.7% had bachelor's degrees and above, 80.8% of operating room nurses were graduated from nursing program. 68.9% of the participants reported that they had lived at least once during their working life. There were significantly different for NSI (p<0.05) women, married and had low educational levels, workingin university hospitals with deep invasive intervention and using protective equipment. Participants reported that 54.8% of the injuries were performed in the right hand and the primary cause was exchanging instruments between nurse and surgeon, the secondary was assisting surgeon. Most of the participants (37.1%) were injured by the suture material. The most common NSI encountered operating theaters were pediatric surgery, cardiovascular surgery, thoracic surgery and general surgery.