Forest inventories have traditionally been used for acquiring quantitative and qualitative information of forests and for formulating management and conservation strategies of forests in Pakistan. It involves intensive and time consuming field surveys of rigid forest environments and entails high costs. However, with the advent of technology, remote sensing offers an alternative tool for acquiring forest data intended for forest mapping and consequently for effective forest management and monitoring. This research produces estimates for forest crown closure with SPOT 5 (2.5 m spatial resolution) and ALI (30 m spatial resolution) imageries. Ayubia National Park was selected as the study area for this research because the National Park has diverse varieties of coniferous and broadleaved tree species in their natural environment. Forest crown closure was assessed for each pixel of SPOT and ALI imageries by employing indices and principal component analysis. It was found that crown closure of Ayubia National Park generally falls between 45 and 65%. A comparison of results obtained from SPOT and ALI imagery was carried out. Accuracy assessment was obtained by using ground data of crown closure measurements.