Background. Despite evidence that obesity and related behaviors are influenced by social networks and social systems, few childhood obesity initiatives have focused on social network factors as moderators of intervention outcomes, or targets for intervention strategies. Objectives. This pilot study examines associations between maternal social network characteristics hypothesized to influence health behaviors and the target outcomes of a family-centered childhood obesity prevention initiative. The pilot intervention entailed the provision of healthy eating and activity components as part of an existing home visiting program (HVP) delivered to mothers and infants, to test the feasibility of this approach for improving mother diet, physical activity, and weight status, as well as infant diet and weight trajectory. Methods. Mothers and their infants (N=50 dyads) receiving services from our HVP partner were recruited and randomized to receive the HVP core curriculum with or without a nutrition and physical activity enhancement module for six months. Assessments of mothers’ social network characteristics, mother/infant food intake and mother physical activity, and mothers’ postpartum weight retention and children’s growth velocity were conducted at baseline and post-intervention. Results. Several features of mothers’ social networks, including the receipt of health-related social support, were significantly associated with the focal intervention outcomes (p < .05) at follow-up, controlling for study condition. Conclusions. Integrating childhood obesity prevention into HVPs appears promising. Future family-based interventions to prevent childhood obesity may be enhanced by including social network intervention strategies. For example, by addressing family network characteristics that impede healthy behavior change, or enhancing networks by fostering social support for healthy behavior and weight change.