Background: Substance use disorders are often accompanied by irrational beliefs and unfavorable attitudes that contribute to their development and persistence. Metaphor therapy, utilizing stories and imagery, has emerged as a potential intervention to reshape thoughts. This study aimed to investigate the impact of metaphor therapy on irrational beliefs and attitudes among individuals with substance use disorders. A quasi-experimental study was conducted at Assiut University Hospital’s substance use inpatient unit. A non-probability purposive sample of 100 were recruited and randomly assigned to study and control groups. Irrational beliefs and attitudes toward substance use were assessed using the Irrational Beliefs Scale and Attitude toward Substance Abuse Questionnaire at pre-treatment, post-treatment, and follow-up. Results The metaphor therapy group demonstrated significant decreases in mean irrational belief subscale and total scores at post-treatment and follow-up compared to pre-treatment. Additionally, this group exhibited higher mean attitude scores, indicating more negative attitudes (rejection of substance use) during post-treatment and follow-up assessments. Conclusions Metaphor therapy was effective in reducing irrational beliefs and fostering more favorable attitudes toward substance use. The finding suggests metaphor therapy could be a valuable intervention for addressing cognitive and attitudinal factors contributing to substance use.