aims: Among different causes, operating room traffic is known to be a factor in surgical site infection and surgical team distraction. Therefore, it is essential to reduce door openings during operation. The purpose of this study was to investigate the impact of the A3 method on operating room human traffic. methods: The present study with a quasi-experimental, two-group and three-stage intervention design was conducted for three months in the operating rooms of Ayatollah Kashani Hospital of Isfahan in Iran. The study samples were selected by census method. The door openings were counted in the first and third phases and the intervention with the A3 method was carried out in the second phase for one month. Data collection tools include a digital counter and a time attendance machine mounted on the operating room door, as well as a researcher-made checklist to record the specifics of each operation and the factors causing the traffic. Data were analyzed by SPSS version 22 software using descriptive statistics. Results: The use of the A3 intervention resulted in a 46% reduction in traffic. On average, door openings per operation decreased from 54.9 times to 31.09 times. Conclusions: The A3 method as one of the processes of Lean management can be effective in reducing the operating room traffic