This article describes Interpersonal and Social Rhythm Therapy (IPSRT) adapted for use in a group setting for patients with bipolar disorder. In a preliminary efficacy study, we studied the pre-post group treatment effect on affective symptoms. One-year pre-post findings in the IPSRT group indicated that this modality was effective in reducing depressive symptoms and might reduce the number of hospital admissions. Also, group IPSRT increased stability of the social rhythm, which is thought to be important in reducing recurrence of manic and depressive episodes. These findings suggest that group IPSRT could be an additional treatment option for patients with bipolar disorder who continue to have mood episodes despite adequate pharmacotherapy and psychoeducation.