Abstract Seventeen Y-chromosomal short tandem repeats (STRs) (DYS19, DYS385, DYS389I, DYS398II, DYS390, DYS391, DYS392, DYS393, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATA H4.1) were typed in DNA samples from 146 unrelated adult Romani Bayash men from eastern and northwestern Croatia. Analysed Croatian Bayash Romani population represents an example of genetically homogenous population characterised by low levels of haplotype diversity and unique haplotype ratio as well as sharing of the same most frequent (founding) haplotype and its close derivatives by more than one third of the analyzed men. Despite almost exclusive sharing of the same minimal haplotype and its closely related derivates on the background of the Indian Y SNP haplogroup H1, we observed considerable level of genetic differentiation of Romani populations across Europe that should not be neglected in forensic statistics.