Introduction: Substance dependence is one of the most important factors affecting the quality of life of substance-dependent patients all over the world. The purpose of the present study was to investigate the effect of hope therapy on the general health of substance-dependent patients undergoing methadone maintenance treatment in Semnan city, Semnan province, Iran. Method: the present study was a Quasi-experimental research design using pre-test, post-test and follow along with the control group. Community to study drug dependent patients in methadone maintenance treatment in the Semnan city. The subjects consisted of 40 cases of drug-dependent patients in methadone maintenance treatment in Semnan who were to leave drug-dependency. The patients were divided randomly into two groups and planning. In addition to drug treatment, methadone maintenance treatment group was treated by hope. Hope Therapy was conducted in 8 sessions on the experimental group and the control group in this period was on the waiting list for psychological intervention. All patients participating in the intervention than the demographic questionnaire and general health questionnaire (SF36) there. After the end of treatment and three months after intervention, subjects were re-evaluated by the questionnaires. Results: Analysis of variance showed that the mean scores general health in the experimental group showed a significant change in the post-test and effects of treatment were permanent after three months of treatment. Conclusions: According to the results it can be concluded that Hope therapy is effective on general health, drug-dependent patients in methadone maintenance treatment.