Objectives: Substance abuse, dependence, and addiction are all complicated disorders associated with biological, psychological, social, and spiritual causes. Relapse into substance use is one of the main problems in the treatment of substance abuse. The aim of the present study was to investigate the effectiveness of mindfulness-based relapse prevention interventions in craving, emotion regulation, and aggression among methamphetamine patients in Kashan city. Method: A quasi-experimental research design along with pre-test/post-test and control group was employed for the conduct of this study. The statistical population of this study included male and female methamphetamine users presenting to short-term residence addiction treatment centers and methadone treatment addiction centers in Kashan. Through random sampling, 30 subjects were selected and were assigned to experimental and control groups. Difficulties in Emotion Regulation Scale, Craving Beliefs Questionnaire, and Eysenck and Wilson's Aggression Scale were used for data collection in this study. The experimental group was trained in eight sessions of mindfulness-based relapse prevention interventions. After the completion of the training interventions, both groups were re-evaluated in the post-test phase. Results: The results of this study showed that there is a significant difference between the two groups in terms of craving, emotion regulation, and aggression. The Eta coefficients for the variables of craving, emotion regulation, and aggression were obtained equal to 0. 27, 0. 21, and 0. 53, respectively. Conclusion: Mindfulness-based prevention can be used in addiction treatment clinics.