A meta-analysis of group treatments for bulimia was conducted. Forty outcome reports were coded on treatment, design, and subject variables. Effect sizes represent pre-treatment to post-treatment changes in bulimia symptoms. The weighted average effect size for group treatment was +0.75 at posf-treatment, suggesting moderate efficacy. Improvement was typically maintained in studies reporting 1 year follow-up data. Larger post-treatment effect sizes were associated with more hours of therapy per week and with the addition of other treatment components, such as individual therapy. The implications of the results for future research and clinical endeavors are discussed.