Prior research in individual therapy has provided evidence that therapists are poor predictors of client outcome and often misjudge clients' perceptions of the therapeutic relationship. The focus of the current research was to conduct a similar predictive study in a group setting. Group therapists were recruited from a university counseling center and a state psychiatric hospital; 64 group members and 10 group leaders participated in the study. We tested therapist accuracy in predicting client outcome and perceived quality of therapeutic relationship. Results suggested that therapists underestimate the number of clients who deteriorate during therapy and were unable to accurately predict client perceptions of the group relationship, replicating findings from larger samples in the individual literature. Results suggest that using outcome and process measures as feedback tools may be also useful for clinicians leading groups.