Summary Karyological analysis and morphometrics of the lesser Asiatic house bat (Scotophilus kuhlii) from Thailand were studied. Blood samples were taken from 5 male and 5 female bats, lymphocytes were cultured at 37 C for 72 h in presence of colchicine, and metaphase spreads were performed on microscopic slides and air-dried. Conventional staining and GTG-banding techniques were applied to stain the chromosomes. The results showed that the diploid chromosome number of S. kuhlii was 2n=36, and the fundamental number (NF) was 52 in both male and female. The types of autosomes were 6 large metacentric, 4 large submetacentric, 6 large telocentric, 2 medium submetacentric, 10 medium telocentric, 2 small metacentric, and 4 small telocentric chromosomes. The X chromosome was a large submetacentric chromosome and the Y chromosome was the smallest acrocentric chromosome. The GTG-banding technique, indicated that the number of bands and locations in S. kuhlii was 167, and that each chromosome pair could be clearly differentiated. In addition, a pair of long arms near the centromere of chromosome pair 17 showed clearly observable nucleolar organizer regions (NORs). In terms of morphological measurement, the following measurements were taken 6 external morphological characters as well as 13 cranial and dental characters. The karyotype formula of S. kuhlii was as follows: