Background & Aims: Midwifery activity is one of the most essential cares in obstetrics and gynecology services, which plays an important role in improving maternal and neonatal health. With increasing global concern about the effects of childbirth and the importance of this process, any human error in this regard is non-negligible. Therefore, given the significant mortality and adverse effects, safe and effective delivery control is a critical issue. Materials & Methods: This cross-sectional study was performed to identify and evaluate midwifery staff errors of Kowsar Hospital of Qazvin in 2018. There are various ways to identify, evaluate, and predict human errors. Among these, the Sherpa technique is one of the most common methods to detect these errors. Results: After hierarchical analysis, the main tasks were divided into 68 sub-tasks. Finally, 65 errors were identified for midwifery staff activities (57% action errors, 25% revision errors, 6% retrieval errors, 9% communication errors, and 3% selective errors). Therefore, the highest percentage was the action errors and the least was the selective errors. Conclusion: Hospital authorities should pay more attention to action errors and prioritize these errors in patient safety. It is recommended that appropriate actions be taken to establish a culture of patient safety.