The following paper outlines a study conducted on the abundance, distribution, and diversity of butterflies in Mt. Koritnik. located in the Republic of Kosovo, during 2019-2022. This research resulted in a total of 8166 recorded specimens, which belonged to 6 butterfly families, 50 genera and 131 species. The richest family in terms of abundance was Nymphalidae with 4611 specimens (56.47%), followed by Lycaenidae 1924 specimens (23.56%), Pieridae 856 (10.48%), 561 Hesperiidae (6.87%), Papilionidae 179 specimens (2.19%) and Riodinidae with 24 specimens (0.29%). In terms of species richness, Nymphalidae were the richest with 55 species, Lycaenidae 40, followed by 15 Pieridae, 15 Hesperiidae, 5 Papilionidae and 1 Roidinidae. Among 131 registered species, 11 have Near Threatened status in Europe. Our results indicated that species richness and abundance of butterflies were significantly negatively correlated with altitude (p<0.01), whereas they showed a strong positive correlation (p<0.01) with the temperature. The highest abundance and number of species were presented in the lower altitudinal range and the numbers decreased with altitude increasing. Activities such as intensive agriculture, grazing, fires and illegal timber cutting, which were observed during our survey, may be the main threats for butterflies in Mt. Koritnik in the future, therefore, we suggest the data from this research serve as a basic information for authorities to monitor future changes in butterfly diversity.