Allele and haplotype frequencies of 17 chromosome STR loci, 15 of them included in the kit PowerPlex 16 System from Promega, were determined in a sample of unrelated males from Madeira and Porto Santo Islands. PowerPlex 16 includes STRs not studied before in the Madeira population. The-kit includes two new allele markers (Penta D and Penta E), which proved to be extremely useful for paternity testing (PD = 0.952 and 0.977, respectively). The study revealed that the Madeira population does not differ from that of the north Portugal. Nevertheless, some loci presented alleles found in sub-Saharan and North European populations which were not reported so far in Portugal.