This study investigated three aspects of patients' interpersonal functioning as predictors of outcome for two forms of group psychotherapy for complicated grief. Patients presented with a variety of death losses and met criteria for complicated grief. The three aspects of interpersonal functioning were the patient's (1) attachment to the lost person, (2) quality of object relations (QOR), and (3) level of recent social role functioning. A more secure attachment to the lost person and better social role functioning were associated with more favorable outcome in both forms of therapy. In addition, patients with higher QOR had more favorable outcome in interpretive therapy while lower QOR patients had more favorable outcome in supportive therapy. The results suggest that each aspect of interpersonal functioning is important to consider when treating patients for complicated grief.