This study was conducted to find out factors affecting patient safety management activities at nursing devisions of two university hospitals. The indicators of patient safety activities used in the study were selected from Hospital Survey on Patient Safety Culture which was developed by The Agency for Healthcare Research and Quality in the United States. Data were collected from 372 nurses working at inpatient wards at two university hospitals located in Seoul and Won-Ju cities through the self-administered questionnaires, and analyzed using frequency analysis, t-test, correlation, and regression analysis. The result of this study were as follows. First, The mean of patient safety management activities was 3.41 which was a little bit higher than the average level. The mean of communication within the ward was the highest, whereas that of patient safety management culture was the lowest. Second, there were significant differences in the perception of nurses on patient safety management activities in terms of the educational background, length of employment, and work hours per week. Third, three variables of communication within the unit, attitude of top management, and attitude of nurses have significant positive effects on patient safety management activities. Fourth, 37.4% of the variation in the patient safety management activities was explained by the study variables. In conclusion, hospital administration and nursing managers should make an effort to learn the knowledge of patient safety program, show their deep interest on the patient safety to the employees and motivate them to communicate effectively each other within the work unit to develop a good patient safety culture and system.