To describe obesity prevention practices and environments in Head Start, the largest federally funded early childhood education program in the United States. Self-administered survey as part of the Study of Healthy Activity and Eating Practices and Environments in Head Start (SHAPES). Head Start, 2008. Directors of all 1810 Head Start programs, excluding those in US territories. Descriptive measures of reported practices and environments related to healthy eating and gross motor activity. The 1583 (87%) programs responding to the survey enrolled 828 707 preschool children. Of these programs, 70% reported serving only nonfat or 1% fat milk. Ninety-four percent of programs reported that each day they served children some fruit other than 100% fruit juice; 97% reported serving some vegetable other than fried potatoes; and 91% reported both of these daily practices. Sixty-six percent of programs said they celebrated special events with healthy foods or nonfood treats, and 54% did not allow vending machines for staff. Having an on-site outdoor play area at every center was reported by 89% of programs. Seventy-four percent of programs reported that children were given structured (adult-led or -guided) gross motor activity for at least 30 minutes each day; 73% reported that children were given unstructured gross motor activity for at least 30 minutes each day, and 56% reported both of these daily practices. Most Head Start programs report doing more to support healthy eating and gross motor activity than required by federal performance standards in these areas.