Purpose: The purpose of this study was to identify the effects of perceived organizational support on organizational commitment and career commitment of nurses. Method: The subjects of this study were 336 nurses who were working in the 6 hospitals. The data were collected by structured questionnaire from Oct. 9 to Nov. 7 of 2006. Data were analyzed using descriptive statistics, t-test, ANOVA, Scheffe test, Pearson correlation coefficients, and multiple regression. Results: The mean score of POS was 2.87, organizational commitment was 3.30 and career commitment was 3.08. The POS was positively correlated with organizational commitment and career commitment. The POS and marital status explained 21.3% of the variance for affective commitment, 12.1% of the variance of continuous commitment. The POS and career explained 14.8% of the variance for career commitment. Conclusion: The findings showed that POS was important factor for enhancing organizational commitment and career commitment of clinical nurses. Therefore, the nurse manager must establish the strategies to improve the POS of the nurses in order to promote the organizational commitment and career commitment.