The present study set out to determine the effectiveness of structural family therapy on the formation of communication patterns, parental adaptability and cohesion, and alexithymia in adolescents dependent on online games. In terms of method, the study was quasi-experimental with a pretest-posttest design and a control group. The statistical population consisted of all male and female senior secondary school students in Tehran who were dependent on online games during the 2023–2024 academic year. From among them, 30 adolescents and at least one of their parents who were willing to participate were selected through purposive sampling and randomly assigned to experimental and control groups. The research instruments were the Online Game Addiction Questionnaire (Whang & Chang, 2002), the Family Communication Patterns instrument (Ritchie & Fitzpatrick, 1990), the Family Adaptability and Cohesion Evaluation Scale (Olson, 1985), and the Toronto Alexithymia Scale. Members of the experimental group underwent ten weekly two-hour sessions of structural family therapy, while the control group received no intervention. Data were analyzed using analysis of covariance with SPSS-26. The findings showed that structural family therapy is effective in shaping the communication patterns, adaptability and cohesion, and alexithymia of adolescents dependent on online games and their parents (P<0.01). It is therefore recommended that structural family therapy be used to reduce adolescents' dependency on online games in schools, along with training workshops for families.