A new cytotype was found in a population of mole rats Nannospalax xanthodon from south-eastern Anatolia, Turkey. The karyotype contained 46 chromosomes and 66 autosomal arms (11 biarmed and 11 acrocentric autosomal pairs). The X chromosome was submetacentric and the Y chromosome small subtelocentric. Distinct dark C-bands were observed on all the biarmed chromosomes and on three pairs of acrocentric autosomes. The NORs were detected on the short arms of two subtelocentric pairs of autosomes. The published data indicate considerable chromosomal variation between populations of mole rats in south-eastern Anatolia. The finding of a karyotype with a unique chromosomal number in the karyologically well-studied region of south-eastern Anatolia indicates that the karyotype structuring between mole rat populations may be even more complex than previously realised.