|Abstract:||Although mutual help groups are addressing the mental health needs of millions of Americans, empirical research has not kept pace with the growth and popularity of the movement. The present empirical investigation focuses on one mutual help organization for ex-mental patients and: (a) provides descriptive data on the actual behaviors characterizing the meetings, (b) identifies behaviors occurring within the group meetings which are predictive of positive outcomes for participants, and, (c) explores the value of two helping mechanisms hypothesized to be important in the mutual help context, "helping others", and "receiving support." Positive outcomes for subjects (n = 85) were assessed within two broad domains, the participant's satisfaction with the group as indexed by meeting attendance and participant improvement as indexed by change over time on three adjustment measures. Meeting behavior was coded and frequencies of occurrence were computed for three types of behaviors: behaviors produced by the subject, behaviors received by the subject, and the behaviors of others in the subject's group, or the group context. Separate hierarchical multiple regression analyses were performed using each of the three types of behavioral frequencies to predict participant outcomes. Helping others was associated with both higher rates of attendance and improvement over time in social adjustment, but not with changes in symptomatology. Frequencies of receiving help did not significantly contribute to the prediction of any of the outcome variables. Behaviors occurring in the subject's group context, however, accounted for 38% of the variance in attendance and between 8-16% of the change in adjustment scores. The results for specific behaviors such as Interpretations, Self-disclosure, and Agreement are discussed in light of commonly held beliefs about their role in the functioning of mutual help groups. Overall, the results reveal points of divergence between helping models in the mutual help and group psychotherapy contexts.