This paper presents an analysis of correlation between occurrence of certain Y-STR alleles and Y chromosome haplogroup, as defined by biallelic genetic markers. DNA samples from 134 unrelated men form the Pomerania-Kujawy region of Poland have been typed. For each Y chromosome, its STR haplotype for 9 loci ("minimal haplotype") and haplogroup defined by M9 and M170 markers have been determined. Y chromosomes have been defined as belonging to I* or non-I* haplo¬group. The results suggest that there could be a strong relationship between some of the Y-STR haplotypes and the chromosome assignment to the defined haplogroup.