The purpose of this study was to determine the effectiveness of schema therapy on depression and relapse in heroin-dependent men. Method: This research was a semi-experimental study with pretest-posttest design with control group. To perform this research among people who referedto Tehran addiction treatment clinic in October to February 2017, 40 referees were selected and randomly assigned to experimental (20) and control groups (20). In this study, the experimental group received the Yang Scheme Program for 10 sessions of 90 minutes, while the control group was on the waiting list for the treatment. Participants completed a Beck Depression Inventory and a urine test to measure the substance in the pre-test and post-test phases. Analysis of covariance was used to analyze the data. Results: The results showed that in the post-test stage, schema therapy could significantly reduce depression and relapse rate in heroin- dependent men compared to control group. Conclusion: Schema therapy as a leading method in the field of cognitive-behavioral therapy has therapeutic benefits for heroin addicts and is effective in reducing the relaps problem.