The Western Ghats Forest ecosystem is known for its abundance of flora and is impacted primarily by habitat degradation. The Normalized Difference Vegetation Index (NDVI) was used in this study to assess the vegetation changes over time in three protected areas of Western Ghats, including Idukki Wildlife Sanctuary, Eravikulam National Park, and Parambikulam WildlifeSanctuary, over a 15-year interval (1988-2003 and 2003-2018) using Landsat datasets and ArcGIS 10.6. The result shows that the vegetation in these three protected areas declined dramatically during a decade (1988-2003), perhaps due to anthropogenic activities, deforestation, forest fires, forest plantations, and fragmentation. Historical records confirm that the study areas have been previously subjected to frequent fires, which have deteriorated the forest. In certain locations, clear-felling of forests for plantation was also documented. Later, between 2003 and 2018, vegetation in these areas increased marginally, possibly due to the Government's conservation efforts in protected areas. Further conservation activities in protected area networks, including afforestation with indigenous flora and adequate legal protection, are recommended in this present study.Keywords: Normalized Difference Vegetation Index (NDVI), protected areas, remote sensing, vegetation, Western Ghat
