To investigate the population genetics of 17 short tandem repeat (STR) loci on the Y chromosome in the population of eastern Croatia. We carried out a statistical analysis of the data from previously performed genetic analysis collected during routine forensic work by the Forensic Science Centre "Ivan Vucetić". A total of 220 unrelated healthy men from eastern Croatia were selected for the purpose of this study. Genomic DNA was extracted by Chelex from FTA cards. Y-chromosomal STRs were determined using the AmpFISTR Yfiler PCR amplification kit. The haplotype frequencies were determined by direct counting and analyzed using Arlequin 3.1 and analysis of molecular variance calculated with the Y-chromosome haplotype reference database online analysis tool. A total of 207 haplotypes were recorded, 197 of which were unique (90%). Haplotype diversity was 0.9993, with the most frequent haplotype found in 4 of 220 men (1.8%). Average locus diversity was 0.600, and it ranged from 0.256 for DYS392 to 0.780 for DYS458. Our results were compared with the pattern of Y-chromosome variability in publicly available population samples based on a minimal European haplotype set of 9 STRs and the greatest resemblance was found with samples from the Croatian capital of Zagreb, from Bosnia and Herzegovina, and from Serbia. This is the first description of Y chromosome haplotyping of the population of eastern Croatia, which may serve as a basis for genetic epidemiology and forensic studies. Further studies are needed for characterization of the genetic structure of the Y-chromosome in the modern Croatian population.