The karyotypes of Dryomys laniger and D. nitedula from Turkey were studied using C-banding and AgNOR staining. The standard karyotypes found in both species were fairly similar to previously published data (2n = 46, NF = 92 in D. laniger; 2n = 48, NF = 96 in D. nitedula). The C-banding pattern revealed a relatively small amount of heterochromatin in both karyotypes and C-heterochromatin was concentrated at centromeric areas of most autosomes and the X chromosome. Heterochromatin changes have apparently not been responsible for karyotypic divergences between the studied species. The AgNORs were recorded in the pericentromeric region of two autosome pairs in the complement of D. laniger, and at a single autosome pair of D. nitedula. The complement of D. laniger could be derived from that of D. nitedula after a tandem fusion of two autosomal pairs, and the assumed rearrangement also included the NOR region.