In the past decade, multiple studies have examined the effectiveness of Acceptance and Commitment Therapy (ACT) for substance use disorders relative to other active treatments. The current meta-analysis examined the aggregate effect size when comparing ACT to other treatments (e.g., CBT, pharmacotherapy, 12-step, treatment as usual) specifically on substance use outcomes.A total of 10 randomized controlled trials were identified through systematic searches.A significant small to medium effect size was found favoring ACT relative to active treatment comparisons following treatment. Effect sizes were comparable across studies for smoking cessation (k=5) and for other drug use disorders (k=5).Based on these findings, ACT appears to be a promising intervention for substance use disorders. Limitations and future directions are discussed.