Increasingly, researchers are exploring alternative ways of assessing the impact of 'Health Promoting School' (HPS) initiatives, in recognition of the model's emphasis on achieving change that is both enduring and far-reaching. However, it is still assumed that initiatives will lead to immediate change at the individual level. This paper challenges that view and argues that potential markers of success associated with process need to be identified earlier as a means of supporting schools and teachers. Notwithstanding differences in the way the HPS is conceptualized and implemented, four themes are highlighted that have relevance beyond any one school or country. These were drawn from a process evaluation of a European Network of HPSs Project in Scotland. They highlight the ways in which schools were able to successfully adopt HPS principles and the conditions that need to be in place for the HPS concept to flourish. Such indicators need to be given greater recognition as HPS outcomes if schools are to progress beyond the early stages of project implementation.