Abstract Background & Objectives: Obsessive-Compulsive Disorder (OCD) is an important mental disorder because of its prevalence and associated disability. Patients with OCD have many psychological problems, such as marital satisfaction. It seems essential to pay close attention to the treatment of these patients, who have a high prevalence and many problems. One of the problems that people with OCD report is marital problems. Marital satisfaction is the degree to which couples feel satisfied with their lives together. One treatment approach for psychological problems is positive psychology. Today, there is a high percentage of patients with OCD in modern society, and many psychological problems occur in these people. Although positive psychological treatment has rarely been used to treat the problems of these people, no study has investigated the effectiveness of a positive psychology treatment program on the marital satisfaction of people with OCD. Therefore, this research aimed to investigate the effectiveness of a positive psychology treatment program on the marital satisfaction of people with OCD. Methods: This research was a quasi-experimental type with a pretest-posttest design with a control group. Among the people with obsessive-compulsive disorder aged 25 to 45 who referred to psychology clinics in Yazd city, Iran, in 2023, 30 available qualified volunteers were included in the study: 15 were randomly assigned to the intervention group and 15 to the control group. The inclusion criteria for the subjects in the study were as follows: having OCD with the approval of a psychiatrist, age range of 25-45 years, not using other psychotherapy methods, and not taking medication. The exclusion criteria for the study subjects were as follows: missing a treatment session and not completing the questionnaire. The initial assessment of the subjects lasted for sixty minutes. The subjects' files and information, including treatments performed to date, were also completed. Before the treatment, the subjects signed a consent form for voluntary participation in the study. Participants were assured that information about the research results would remain confidential and that only the researcher would have access to their files for data analysis. They were also free to leave the study at any stage if they wished. The researchers pledged to provide free group therapy sessions for the control group if the results were significant. The Enrich Marital Satisfaction Scale (Fowers & Olson, 1993) was compared before and after 8, 90-minute sessions of group positive psychology therapy. SPSS version 17 software was used for data analysis. In the descriptive statistics section, the mean and standard deviation of the scores for each variable were extracted. In the inferential statistics section, the data were analyzed using analysis of covariance. The significance level of the tests was set at 0.05. Results: The analysis of covariance, adjusted for the pretest effect, showed a significant difference in mean marital satisfaction between the intervention and control groups at the posttest (p<0.001). Based on the effect size results, 64% of the difference between the intervention and control groups in the marital satisfaction component was due to the implementation of group positive psychology therapy. Conclusion: Based on the results of the study, group positive psychology therapy can be used as a complementary therapy to improve marital satisfaction in patients with obsessive-compulsive disorder.