Introduction: Most of intellectually disabled students do not have appropriate adaptive behaviors. Their maladaptive behaviors lead to psychological problems in their life and affect their interactions negatively. Therefore, instructional interventions are required. This study aims to compare the effectiveness of cognitive-behavioral and social competency training methods on adaptive behavior of intellectually disabled boy students in Tehran.Method: This is an experimental study established in pretest and posttest design accompanied by control group; 60 boys were selected from intellectually disabled students aged 12-14 years, using cluster sampling type. Subjects were randomly devided into 3 groups (2 experimental groups and one control group; each group comprising 20 individuals). Experimental groups attended cognitive-behavioral and social competency training sessions (10 sessions of 50 minutes; weekly) but control group did not. All participants were assessed through Vineland’s Adaptive Behavior Scale before and after intervention sessions. Data was analyzed by analysis of covariance and post-hoc Tukey test.Results: Findings showed that there was significant difference between experimental groups and control group. The mean scores of the post-test belonged to cognitive-behavioral training group showed a major difference in comparison to the social competency and control groups. Furthermore, the difference of the mean scores pertaining to social competency training group was significantly more than the control one.Conclusion: The cognitive-behavioral and social competency training programs lead to improvement of adaptive behavior in intellectually disabled students. Therefore, devising such training programs is particularly advantageous to these students.