Numerous studies have shown associations between public open space and a variety of health outcomes. Yet the extent to which firm conclusions and planning policy recommendations can be drawn from this body of work depends on how public open space availability has been measured and reported. Other researchers have highlighted potential issues with the way that public open space has been measured but have not systematically assessed the extent of this problem. This paper provides a comprehensive critical review of studies of public open space and health conducted in Australia to identify and compare public open space measurement and data treatment. Our analysis showed wide variation in how public open space was measured, as well as a lack of consistency in reporting public open space exposure measures and under-reporting of measurement methods. We find that such tendencies limit how much these studies can be compared and contrasted with each other. The corollary of that finding is that without more detailed reporting of exposure measures, it will be difficult to establish an evidence base that informs planning for healthy, liveable environments. In response, we develop and present a checklist for reporting public open space exposure to address this challenge.