ABSTRACT: BACKGROUND:This study evaluates an eight-session behavior change health intervention with women's self-help groups (SHGs) aimed to promote healthy maternal and newborn practices among the more socially and economically marginalized groups. METHODS:Using a pre-post quasi-experimental design, a total of 545 SHGs were divided into two groups: a control group, which received the usual microcredit intervention; and an intervention group, which received additional participatory training around maternal, neonatal, and child health issues. Women members of SHGs who had a live birth in the 12 months preceding the survey were surveyed on demographics, practices around maternal, neonatal and child health (MNCH), and collectivization. Outcome effects were assessed using difference-in-difference (DID) methods. RESULTS:Women from the SHGs with health intervention, relative to controls over time (time 1 to time 2), were more likely to: use contraceptive methods (DID: 9 percentage points [pp], p<0.001), have institutional delivery (DID: 9pp, p<0.05), practice skin-to-skin care (DID: 17pp, p<0.05), delay bathing for 3 or more days (DID: 19pp, p<0.001), initiate timely breastfeeding (DID: 21pp, p<0.001), exclusively breastfeed the child (DID: 27pp, p<0.001), and provide age-appropriate immunization (DID: 9pp, p<0.001). Additionally, women from the SHGs with health intervention when compared to the control group over time were more likely to report: collective efficacy (DID: 17pp, p<0.001), support through accompanying SHG members for antenatal care (DID: 8pp, p<0.05), receive a visit from SHG member within 2 days post-delivery (DID: 32pp, p<0.001), and receive reproductive, maternal, neonatal and child health information from an SHG member (DID: 45pp, p<0.001). CONCLUSION:Findings demonstrate that structured participatory communication on MNCH with women's groups improve positive health practices. In addition, SHGs can reach a substantial proportion of women while providing an avenue for pregnant women and young mothers to be assisted by others in learning and practicing healthy behaviors, thus building social cohesion on health.