Of all DNA markers on the human Y-chromosome, the tetra-local Y-linked microsatellite DYS464 is the most polymorphic. We genotyped DYS464 in 677 male samples collected worldwide, maintained in the HGDP-CEPH Human Genome Diversity Cell Line Panel. Fourteen different alleles were found, with allele lengths varying from 9 to 23 repeats. One hundred and seventy-five different genotypes were detected, of which 90 appeared to be continent-specific. The region with the highest percentage of unique genotypes was Africa.