Taiwan launched its evidence-based health-promoting school (HPS) program via an action-research approach in 2010. The program featured a collaborative partnership between schools, local education authorities and university support networks. This study was focused on examining whether an HPS action-research approach was effective in advancing HPS implementation, perceived HPS impact and perceived HPS efficacy in Taiwan. In 2011, questionnaires were sent to 900 sample schools in Taiwan. A total of 621 schools returned the questionnaire, including 488 primary schools and 133 middle schools. The response rate was 69%. This study compared the difference in HPS implementation status, perceived HPS impact and perceived HPS efficacy between those schools that had implemented action-research HPS (138 schools) and those that had not (483 schools). The univariate analysis results indicated that the HPS implementation levels for components that included school health policies, physical environment, social environment, teaching activities and school-community relations were significantly higher in action-research schools than in non-action-research schools. Teachers in action-research schools reported significantly higher levels of HPS impact and HPS efficacy than non-action-research schools. The multivariate analysis results indicated that after controlling for school level and HPS funding, the HPS action-research approach was significantly positively related to greater levels of HPS implementation, perceived HPS impact and perceived HPS efficacy.