There is an urbanization process on a global scale with population growth and technological developments. Especially in metropolitan cities, mega projects located on the city periphery lead to environmental pressure on natural areas and forests. Istanbul Northern Forests, the transition region of the Black Sea and Mediterranean flora, host various ecosystems due to its pseudomaki structure. However, the effects of big projects recently realized such as Istanbul Airport, Northern Marmara Motorway, and Yavuz Sultan Selim Bridge on the Istanbul Northern Forests can be noticed even with the naked eye. This study investigates land use/cover changes in Istanbul Northern Forests which are under intense urbanization pressure using LANDSAT and SENTINEL-2 satellite images in a time series of thirty-nine years (1984-2023). As a result of the analysis, it is seen that the class of impervious surfaces increased in Istanbul Northern Forests between 1984-2023, while the class of barren land, natural areas and agricultural areas decreased. Landscape metrics such as Total Class Area, Percentage of Landscape, and Interspersion Juxtaposition index were used to better understand the change in the study area between 2017 and 2023.