Background and Aim: One of the common problems in people with obsessive-compulsive disorder and substance abuse is emotion regulation difficult. The aim of this study was to compare emotion regulation strategies in people with obsessive-compulsive disorder, substance abuse and normal people. Materials and Methods: This study was conducted with historical cohort method. 40 patients with OCD, 40 substance abusers by purposive sampling, and 40 healthy people by available sampling, were selected as a control group. Structured Clinical Interview for DSM-IV axis I disorders (SCID-I), Yale Brown obsessive-compulsive scale (Y-BOCS), difficulties in emotion regulation scale (DERS), Emotion Regulation Questionnaire (ERQ) were performed. Results: There was a significant difference (P=0.001) among three groups in all items of emotional difficulties and emotion regulation strategies except suppression. According to the results of binary comparisons there was a significant difference (P=0.001) in all items except suppression between obsessive-compulsive group and normal people. In impulse control difficulties (P=0.004) and limited access to emotion regulation strategies (P=0.001) there was a significant difference between substance abusers and normal people. There was a significant difference in nonacceptance of emotional responses (P=0.001), difficulties engaging in goal- directed behavior when distressed (P=0.009), limited access to emotion regulation strategies (P=0.006) between obsessive-compulsive group and substance abusers. Conclusion: It seems that considering emotion-focused interventions for substance abuse group and all of the emotion regulation subfactors including cognitive methods for patient with obsessive-compulsive disorder be effective in their treatment interventions.