Background and Aim: Considering the role of family, which is one of the main pillars of society, it should be said that achieving a healthy society depends on the family. Family health also depends on the mental health of couples and favorable relationship between them. This study has been conducted into the effectiveness of with solution-focused group therapy in reduction of aggression of couples, between whom the husband is an addict, the couples who go to the parent drug rehabilitation clinic of Mashhad Methods: This is a practical study and a quasi-experimental research methodology with a pretest– post-test control-group design has been used. The population consists of all couples who have gone to the parent drug rehabilitation clinic of Mashhad in (2014). Among all these couples the problem has been drug abuse in husbands. 10 couples with marital conflicts and signs of aggression have been selected from the population through convenience sampling, and they have been replaced randomly in one treatment group and one control group. The required data has been collected through aggression questionnaire (Buss and Perry, 1999),. Then treatment groups receive eight sessions of group therapy (each session is 90 minutes); meanwhile, the control group receives no intervention. Finally, when the group therapy sessions finish, a post-test is given. The results: Findings of the study are analyzed through analysis of covariance (ANCOVA) done with SPSS 21. The results confirm and show that solution-focused group therapy can cause a reduction in aggression of the couples between whom the husband is addict. Conclusion: is more effective in reduction of aggression, and solution-focused group therapy is more effective in reduction of aggression

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