Contact with UGS (urban green spaces) is a critical element for urban quality of life and an essential aspect of environmental justice, so all citizens should be able to access UGS regardless of their social and economic condition. In this regard, several studies have shown a positive correlation between UGS justice with socio-economic status in different contexts. In recent decades, Tehran has also experienced much wider socio-economic inequalities, reflected in its spatial configuration. Therefore, this study explored the possible correlation between the UGS supply and accessibility in the 22 Tehran municipal districts and their socio-economic development level. For this purpose, UGS supply (per capita) and accessibility (areas within 800 m walking distance to UGS) indicators are used to assess the UGS justice in Tehran. The research data are drawn from official spatial and statistical data, analysed using ArcGIS. This quantitative data are converted into map layers to shape a basis for UGS assessment indicators in conjunction with socio-economic status. The findings show an unbalanced distribution of UGS in Tehran. However, the areas with highest socio-economic status are at an optimum level of UGS justice in relation to all 22 districts, but no direct correlation confirms the same results for areas with lower socio-economic status.