Background: Substance abuse is a chronic relapsing disorder that one of its features is experiencing the maladaptive emotions. Research findings suggest that the emotional factors play a pivotal role in craving. The purpose of this study was to investigate the efficacy of group therapy of transactional analysis on adjustment and reduction of emotional schemas in withdrawing addicts. Materials and Methods: This study is an experimental research with a pretest-posttest design with a control group. The study population consisted of all male drug addicts who had referred to addiction withdrawal clinics of Tehran in 2014. A total of 30 drug-dependent persons randomly assigned to the experimental and control groups using the convenience sampling method. Transactional analysis group therapy was applied for the experimental group through ten 90-minute sessions. Data were analyzed by multivariate analysis of variances method with significance level of 0.95 using IBM SPSS 16 software. Results: Analysis of covariance results showed that transactional analysis can reduce maladaptive emotional schemas, validation, rumination, guilt, uncontrollability, blame, rationality, simplistic view of emotions, emotional acceptance, consensus and increasing emotional awareness, comprehensibility, expressiveness and the superior values in the experimental group. Conclusion: Considering that addicted people are more exposed to negative emotions, their rate of control in stressful situations can be increased by educating them in Transactional Analysis.