Background: Substance use disorders are highly prevalent among youth and adult populations. Psychosocial skills training can improve the ability of those patients to cope with emotional distress and the challenges, conflicts, and adversities of everyday life by increasing their emotional regulation skills. Aim: This study aimed to evaluate the effectiveness of psychosocial skills training on emotional regulation among patients with substance use disorder. Design: A quasi-experimental study design was utilized (pretest/posttest and follow up) Setting: El-Abbasia Psychiatric Hospital affiliated to the General Secretariat of Mental Health and Addiction Treatment. Subjects: A purposive sample of 41 patients with substance use disorder with specific inclusion criteria. Tools: four tools were used for data collection namely: Structured interviewing questionnaire, Difficulties in Emotion Regulation Scale, Distress Tolerance Scale, and Interpersonal Competence Questionnaire. Results: This study revealed that there were improvements in interpersonal competence, distress tolerance and difficulties in emotion regulation among patients with substance use disorders post- psychosocial skills training implementation. Also, there were negative correlations between interpersonal competence and difficulties in emotion regulation, and distress tolerance post- psychosocial skills training implementation. While there was a positive correlation between difficulties in emotion regulation and distress tolerance post- psychosocial skills training implementation. Conclusion: Psychosocial skills training had a positive effect on emotional regulation among patients with substance use disorders. Recommendations: Integration of psychosocial skill training in the rehabilitation and relapse prevention programs of patients with substance use disorders to enhance their coping skills and regulate their emotions effectively.