Background: This article proposes a method for analysing the degree of maturity of Health in All Policies (HiAP) among World Health Organization-French Healthy Cities Network (WHO-FHCN) as part of the GoveRnance for Equity, EnviroNment and Health in the City (GREENH-City) project. We focused on the creation or enhancement of health-promoting environments, and more specifically, public green spaces. Methods: We conducted a cross-sectional quantitative study guided by the evaluative framework of the HiAP maturity level developed by Storm et al mixed with a qualitative interpretation. A self-administered questionnaire was sent to elected officials and health department officers in the 85 member cities of the WHO-FHCN in 2017. Subsequently 58...