Allele and haplotype frequencies of 16 chromosome STR loci, 15 of them included in the Kit PowerPlex ( R)16 System from Promega were determined in a sample of unrelated males from the Acores Archipelago. All subjects were subjected to an interview in order to make sure that their ancestors belonged to the same island at least back to three generations. This way we intended to look for possible inter-islands differences. PowerPlex ( R)16 includes STRs not studied before in the Acores population. The Kit includes two new allele markers (Penta D and Penta E), which proved to be extremely useful for paternity testing (PD=0.921 and 0.971, respectively). The study revealed that the Acores population is considerable different from the previous studied Madeira population, but does not differ from that of the north Portugal. Nevertheless, some loci presented alleles not previously reported for Portugal.