Available data on karyotypes of the mammals from Turkey and neighbouring regions (the Balkans, the Caucasus, and the Middle East) were summarized and reviewed in respect of their implications to taxonomy and systematics. In this review, previously unpublished data are presented in 20 species. Terrestrial mammals were taken into consideration, both the native and introduced. Altogether, 156 species occurring in the region concerned were included. The karyotype was studied in 109 of these species in Turkey, in most other species data are available from other geographic regions, and only three species remain unstudied cytogenetically. Intraspecific chromosomal variation (polymorphism or polytypy) was reported in 22 species. A karyotype different from the findings made in other regions was reported in Turkish populations of 17 species. Possible future directions of the cytogenetic investigations of mammals in the region are proposed.