Green spaces are an integral part of urban landscape and offer numerous benefits related to quality of urban life. However, due to various factors, the distribution of green spaces among city neighbourhoods is often skewed. Hence, urban planners require effective tools to routinely map and monitor the greening/ un-greening phenomena among the neighbourhoods. This study caters to this need by adopting a geospatial green space distribution assessment approach that encompasses green space quantity, quality and accessibility aspects. The green space distribution indicators were derived from remote sensing data, which facilitates cost-effective green space assessments at desired time scales. In this study, the approach is demonstrated in Mumbai, a typical city in a developing country undergoing urbanization transition accompanied by stark environmental challenges. The study results revealed that the green spaces in Mumbai had generally diminished, fragmented and disaggregated between 2001 and 2011. However, the level of degeneration of green spaces was found to vary significantly among the neighbourhoods. The results also unveiled that the verdant spaces in the city's western suburbs had experienced the worst degradation during the study period. These results would aid Mumbai's planners in formulating local greening strategies in a cost-effective manner. Further, the study has wider implications for green space planning, especially in the understudied, fast-urbanizing developing countries.