This study evaluated the effectiveness of group cognitive-behavioral treatment (CBT) and group interpersonal psychotherapy (IPT) for binge eating. Fifty-six women with nonpurging bulimia were randomly assigned to 1 of 3 groups: CBT, IPT, or a wait-list control (WL). Treatment was administered in small groups that met for 16 weekly sessions. At posttreatment, both group CBT and group IPT treatment conditions showed significant improvement in reducing binge eating, whereas the WL condition did not. Binge eating remained significantly below baseline levels for both treatment conditions at 6-month and 1-year follow-ups. These data support the central role of both eating behavior and interpersonal factors in the understanding and treatment of bulimia.