This article describes a process for establishing school nutrition advisory councils (SNACs) as an integral part of a school environment approach to promoting the nutritional health of students. The application of social cognitive theory as the conceptual framework for SNACs is discussed and the steps for establishing councils, including describing the school food environment, recruiting council members and convening the council, are reviewed. Actions taken by SNACs to positively affect the school nutrition environment are also described. SNACs are 1 component of the Teens Eating for Energy and Nutrition at School (TEENS) study, a group randomized, school-based intervention trial conducted in 16 middle schools in the Minneapolis-St Paul, Minn, metropolitan area. TEENS seeks to promote healthful dietary behaviors among young adolescents to reduce future cancer risk. Primary outcome measures include increasing fruit and vegetable intake and decreasing fat consumption. SNACs were established in the intervention schools to assess the overall school food environment and to advance school-level policy that promotes a healthful food environment.