The helping transactions that occur in group meetings have been theorized to be important therapeutic mechanisms within mutual-help (or self-help) groups. Hypothesized links between giving and receiving help and psychosocial adjustment were examined in a mutual-help group for individuals with serious mental illness (GROW). Participants' adjustment was assessed at two time points and helping behaviors were measured with observational coding of weekly group interactions during the period between assessments. Frequencies of helping behaviors were used to predict Time 2 adjustment after controlling for initial adjustment. Consistent with the helper therapy principle, giving help to others predicted improvements in psychosocial adjustment; giving advice was a unique predictor. Total amount of help received was not associated with adjustment, but receiving help that provided cognitive reframing was associated with better social adjustment. A predicted interaction suggested that receiving help was related to better functioning when members experienced high levels of group integration.