There is substantial evidence of links between green spaces and better health status. However, the ways in which green space are measured are varied, including both objective and subjective measures. This paper examines factors associated with individuals’ perceiving a lack of open public space, including the objective quantity of green space and wider problems in the area. This is analysed using a combination of principal component analysis and logistic regression. We use data from the Healthy Ireland Survey 2016, a cross sectional survey of over 7000 adults in Ireland. The results suggest that objective green space has a significant negative association with whether an individual perceives a problem with lack of open public space. The analysis also reveals that area safety, area cleanliness, and area service provision are important factors explaining perceived adequacy of open public space. The findings of this analysis have implications for the methods by which researchers and policymakers measure and analyse green space in an area.