Allele frequencies, together with some parameters of forensic interest, for 15 STRs included in the Powerplex 16 System (CSF1PO, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, FGA, Penta D, Penta E, TH01, TPO and VWA) were estimated from two samples of unrelated individuals from Tunisia, of different ethnicity: Kesra (Berber) and Zriba (Arab). No deviations from Hardy-Weinberg equilibrium were observed after Bonferroni's correction for the number of loci analysed. Comparative analyses between our population data and other North African databases showed that significant differences were concentrated on loci with lowest values of diversity (mainly CSF1PO and D13S317), irrespective of ethnicity and geographic location.This work was partially supported by the Tunisian Ministry of Higher Education, Scientific Research and Technology. Fundacao para a Ciencia e a Tecnologia conceded a research grant to L.P. (SFRH/BPD/7121/2001) and partially supports IPATIMUP by Programa Operacional Ciencia, Tecnologia e Inovacao (POCTI), Quadro Comunitario de Apoio III
