Introduction: Patient safety is one of the most important issues in health care systems of developed countries. This study attempted to develop strategies and preventive measures for medical errors in public hospitals in Tehran.

 Methods: This is a descriptive survey in which the population included all process owners (12 person teams) of public hospitals in Tehran. The sample size was 396 individuals selected by stratified sampling. A questionnaire was used for data collection. Following the data collection, factor analysis was used to analyze the data.

 Results: The process owners (12 person teams), acknowledged the use of 12 strategies, accounted for 48.24% of the total variance, to prevent medical errors. The most and the least powerful strategies were related to human resources management and teamwork with the percentages of 7.81 and 1.93% respectively.

 Conclusion: The public hospitals in Tehran can improve the quality of clinical services by applying preventive measures, especially in the area of human resources management, through persuading health service providers to take an initial diagnostic test and to participate in periodic competency and empowerment courses.