Urban open space provides a number of valuable services to urban populations, including recreational opportunities, aesthetic enjoyment, environmental functions, and may also be associated with existence values. In separate meta-analyses of the contingent valuation (CV) and hedonic pricing (HP) literature we examine which physical, socio-economic, and study characteristics determine the value of open space. The dependent variable in the CV meta-regression is defined as the value of open space per hectare per year in 2003 US$, and in the HP model as the percentage change in house price for a 10 m decrease in distance to open space. Using a multi-level modelling approach we find in both the CV and HP analyses that there is a positive and significant relationship between the value of urban open space and population density, indicating that scarcity and crowdedness matter, and that the value of open space does not vary significantly with income. Further, urban parks are more highly valued than other types of urban open space (forests, agricultural and undeveloped land) and methodological differences in study design have a large influence on estimated values from both CV and HP. We also find important regional differences in preferences for urban open space, which suggests that the potential for transferring estimated values between regions is likely to be limited. © 2011 Elsevier Ltd.