Background: Incorrect surgical counts are closely related to retained surgical items, which pose a threat to patients. However, the risk factors for incorrect surgical counts have not been identified yet.Aim: To identify the risk factors associated with incorrect surgical counts during surgery in a tertiary hospital.Design: An observational case-control study.Methods: Seventy cases of incorrect surgical counts were reviewed in this study.Data were collected from January 1, 2014, to April 4, 2019. For each case, we included four randomly selected control cases involving the same surgical procedures by the same surgeon within a 6-month period for comparison. The medical data of these cases were extracted for further statistical analysis.Results: A higher incidence of incorrect surgical counts was observed among surgical counts performed between 8:00 a.m. to 12:00 a.m., emergency operations, prolonged procedures, and/or after addition of surgical items. Conclusion:Prolonged surgical procedures, emergency operations, time of occurrence, and addition of surgical items were the risk factors related to incorrect surgical counts during surgery.