Objectives : The aim of the present study was to investigate the role of positive and negative perfectionism, self-efficacy, worry and emotion regulation in predicting behavioral and decisional procrastination. Method: In current correlational study, 365 students from Tehran University completed General Self-Efficacy Scale (GSES), Difficulties in Emotion Regulation Strategies Scale (DERS), Worry Domains Questionnaire-Short Form (WDQ), Positive and Negative Perfectionism Scale (PNPS), Decisional Procrastination Scale (DPS) and General Procrastination Scale (GPS). The gathered data was analyzed using Pearson correlation and stepwise multiple regression. Results: All variables were correlated with the behavioral and decisional procrastination (p<0.01). The stepwise multiple regression analysis indicated that the predictive model for behavioral procrastination consisted of general self-efficacy, difficulties in emotion regulation, positive perfectionism and worry, respectively (p<0.001). Negative perfectionism excluded from this model. For decisional procrastination the model included difficulties in emotion regulation, worry, positive and negative perfectionism (p<0.001). Conclusion: Current study emphasized the multifaceted nature of procrastination and the importance of cognitive and emotional variables in understanding procrastination . The results also confirm the detrimental role of emotion regulation in psychopathology of procrastination. However, this research wasn’t based on an integrated theoretical model about procrastination.