Introduction: Patient safety is one of the main components of health service quality, and patient safety culture is considered as one of the necessary factors in promotion of the patients’ safety. On the other hand, the application of critical thinking skills, by developing evidence-based practices, leads to positive outcomes in patients. This study aims to determine the relationship between critical thinking and patient safety culture in the nurses. Methods: This correlational study was conducted on 196 nurses working in Shariati Hospital of Isfahan city who had been selected by convenience sampling method. Data was collected by hospital survey on patient safety culture (HSOPSC) questionnaire and the California critical thinking skills test; form B (CCTST). The data was analyzed by descriptive statistics and Pearson correlation test in SPSS 22 software. Results: Most of the participants (52. 6%, 103 persons) were woman and were in the age group of 31-40 years (35. 2%, 69 persons). The mean score of patient safety culture in study samples was 3. 03± 0. 45 which was at a weak level. Also, the mean score of nurses’ critical thinking was 29. 74 ± 3. 36 which had a desirable level. A significant direct relationship was found between patient safety culture and nurses’ critical thinking; so that improvement of the nurses’ critical thinking led to promotion of patient safety culture (r=0. 338, P<0. 001). Conclusions: According to the results of this study, improvement of the nurses’ critical thinking can help to promote patient safety culture. Therefore, it is necessary for nursing managers and nursing education policy makers to plan for promoting critical thinking of nurses and nursing students as one of the ways to develop the patient safety culture, to provide the necessary context for improving patient safety and ultimately improving the quality of nursing care.