Excess weight gain in American Indian/Alaskan native (AI/AN) children is a public health concern. This study tested (1) the feasibility of delivering community-wide interventions, alone or in combination with family-based interventions, to promote breastfeeding and reduce the consumption of sugar-sweetened beverages; and (2) whether these interventions decrease Body Mass Index (BMI)-Z scores in children 18-24 months of age. Three AI/AN tribes were randomly assigned to two active interventions; a community-wide intervention alone (tribe A; n = 63 families) or community-wide intervention containing a family component (tribes B and C; n = 142 families). Tribal staff and the research team designed community-tailored interventions and trained community health workers to deliver the family intervention through home visits. Feasibility and acceptability of the intervention and BMI-Z scores at 18-24 months were compared between tribe A and tribes B & C combined using a separate sample pretest, posttest design. Eighty-six percent of enrolled families completed the study. Breastfeeding initiation and 6-month duration increased 14 and 15%, respectively, in all tribes compared to national rates for American Indians. Breastfeeding at 12 months was comparable to national data. Parents expressed confidence in their ability to curtail family consumption of sugar-sweetened beverages. Compared to a pretest sample of children of a similar age 2 years before the study begun, BMI-Z scores increased in all tribes. However, the increase was less in tribes B & C compared to tribe A (-0.75, P = 0.016). Family, plus community-wide interventions to increase breastfeeding and curtail sugar-sweetened beverages attenuate BMI rise in AI/AN toddlers more than community-wide interventions alone.