Introduction: Shortage of professional nursing staff has become a serious challenge in our country; so, retaining committed nurses is a competition between hospital managers and nurse managers.Aim: This study was done to determine predictors of organizational commitment among nurses.Methods and Materials: In this descriptive – correlational study, 400 questionnaires were distributed among nurses employed in 15 hospitals affiliated to Tehran University of Medical Sciences in Tehran, through multi-stage cluster sampling in 2012. Data collecting tools were, Linz’s organizational commitment questionnaire (2003), Alterman’s job satisfaction questionnaire (2007) and Niehoff and Moorman’s organizational justice scale (2005).In this regard, validity, internal consistency coefficient were approved through content method and confirmed Cronbach’s Alpha, respectively (0.75, 0.77, 0.88). Data were analyzed using SPSS18 software by regression coefficient, stepwise regression and descriptive statistics (a<0.05).Results: findings from multiple regression showed that job satisfaction and procedural justice explained 28 and 11 percent (totally 39 percent) of nurses' commitment variance respectively, which was statistically significant (P<0.001).Of course, nurses ‘point of view, justice of head nurses and nurse managers to implement procedures was “relatively unfavorable” and “lower than mean” but mean of job satisfaction and organizational commitment was 3.37±0.76 and 3.36±0.8 respectively. There was significant and positive relationship between and Job satisfaction (P<0.01, r=0.52) and perceived procedural justice (P<0.01, r=0.53) with organizational commitment.Conclusion: It is suggest to nurse managers and health-care managers for retaining committed nurses provide conditions for better satisfaction. And they promote organizational justice in nurses' perception by performance appraisal and feedback to nurses fairly in variety situations.