Common ash (Fraxinus excelsior L.) forms stands of significant ecological and economic importance. However, a progressing phenomenon known as ash dieback has been recorded in Europe since 1992. The cause is primarily attributed to the fungus Hymenoscyphus fraxineus, but the initial factor allowing for the pathogenic role of fungi may be the weakening of the stands related to changing habitat conditions. Standard (ground-based) analysis of habitat conditions is tedious and costly, but remote sensing methods allow for the use of new tools. Among these are spectral indices, including the normalized difference vegetation index (NDVI). The aim of the study was to demonstrate the usefulness of this index in assessing habitat conditions of ash stands in Poland, a country located at the center of the Fraxinus excelsior range. By testing all ash stands in Poland where the share of ash in the stand was at least 80%, habitat conditions diversity covering 19 forest habitat types and 15 soil types was demonstrated. The conducted statistical analyses indicate that the tested habitat parameters affect NDVI in a complex and non-linear manner. The analysis showed that stand age has a minimal impact on NDVI. This means that other factors are responsible for the rapid drops in NDVI values. Differences in NDVI values can be considered the resultant of various habitat factors, illustrating better or worse conditions for a given stand type. Thus, the NDVI index can serve as a decision-support tool for evaluating the extent to which a given forest habitat type meets the ecological requirements of common ash.