This study examined the mediating effect of positive and negative achievement emotions on the relationship between causal attributions and academic self-regulation among university students. On a sample consisting of 270 students (93 male 177 female) were administrated the achievement emotion questionnaire (Pekrun, Goetz & Perry, 2005).), attributin style questionnaire (Peterson, Semel, Beayer, Abramson, Metalsky & Seligman, 1982) and academic self-regulation scale (Ryan & Connell, 1989). Structural equation modeling was used to assess the mediating effects model of achievement emotions on the relationship between causal attributions and academic self-regulation. results showed that there is a positive significant correlation between adaptive attribution style with positive achievement emotions and a positive significant correlation between nonadaptive attribution style with negative achievement emotions and positive significant correlation between positive achievement emotions with self-regulation and negative correlation between negative emotions and academic self-regulation. Results also indicated that the relationship between adaptive and non-adaptive attribution styles and academic self-regulation by positive and negative achievement emotions is mediated. All of the regression weights in the both models were statistically significant and in the the mediating model of positive and negative achievement emotions, models' predictors accounted for 25% and 21% of the variance in academic self-regulation, respectively. In sum, the results emphysising on the mediating role of achievement emotions, provide further support for the attribution theory.