This study evaluated a peer-support program for low-income mothers that is designed to serve the objectives of (1) enhancing the parents’ competence, (2) reducing their stress and tension, and (3) building social support networks for parents. This program involves a service delivery model that is characterized by community-based, social worker- and parent-mentor-led support groups, with informal group support at a later stage. We evaluated whether the program was effective for enhancing the social support, psychological well-being and parenting competence of the users. We also identified the most crucial elements of peer-support services for disadvantaged mothers. In conducting this study, we applied a mixture of quantitative and qualitative methods in three phases. For the quantitative study, two groups (service user and control) were examined three times over a 6-month period. For the qualitative study, we constructed a purposeful sample by drawing mothers from the pool of parents who had participated in the program, and conducted focus-group interviews with these mothers at three points, parallel to the quantitative study. The results suggested that the community-based peer-support group program is effective. There is, however, a need to strengthen the models of peer support by better defining the respective roles of the parent participants, the peer counselors and the social workers. More fundamentally, there is a need to clarify the basic philosophy of the program along the continuum of professional/expert-vs. indigenous/peer-led participants. The program also needs to better capture the strengths of peers and mentors in its peer-support group model.