The incidents arising from care have been the target of worldwide discussion, reflecting on improving the quality and safety of care, as important indicators. This study aimed to identify the prevalence of incidents in the operating room in a teaching hospital in Central Brazil. This was a retrospective cross-sectional study. Data was collected through analysis of 700 medical records of patients older than 18 years undergoing clean surgeries from 2013 to 2015. We found a prevalence of 6% (n=42) incidents during surgery, 14.3% (n=6) related to the structure and 85.7% (n=36) to the process. Of these, 69% (n=29) related to patient safety and 31% (13) related to worker safety. This study provides subsidies for (re)formulation of preventive strategies and the formation of a safety culture.