Public health is increasingly emphasizing policy, systems, and environmental (PSE) change as a key strategy for population-level health promotion and disease prevention. When applied to childhood obesity, this strategy typically involves school systems, since children spend large portions of their days in school and are heavily influenced by this environment. While most school systems have implemented nutrition education and physical activity programs for some time, their understanding and use of PSE approaches to obesity prevention is accelerating based on several large federally funded initiatives. As part of one initiative's evaluation, key informant interviews reveal the specific obesity prevention PSE strategies schools are attempting and the corresponding barriers and facilitators to their implementation. These evaluation findings raise several fundamental issues regarding school-based obesity prevention, including the potential role of school personnel, the influence of grant funding on school health initiatives, and the fit between public health and educational priorities.