The Western Australian School Health Project (WASH Project) is an intervention that encourages schools to develop comprehensive health promotion programs. The WASH Project works with self-selected school communities and uses community development strategies to support participating schools in identifying and responding to health concerns relevant to their students. The study reported here was designed to assess the impact of the WASH Project intervention on changes to a school's structural commitment to comprehensively promote health. School structural factors include both management factors, which identify a schools commitment to health promotion, and health promotion factors, which help to identify the breadth of a school's health promotion program. The study employed a quasi-experimental research design with pre-test, post-test and a control group. In this instance the WASH Project has demonstrated an ability to involve the school in health promotion to the extent that it is willing to provide both monetary and human resources to the development of school health promotion, and to adopt policy to reinforce this change. These structural improvements indicate that relatively modest external interventions, such as the WASH Project, can influence the way a school operates to increase adoption and development of comprehensive health promotion programs.