A study of the genetic variability in the Chueta (Majorcan Jews) and the Balearic (Majorca and Minorca Islands) populations was carried out using a multiplex system containing the nine tetrameric STRs D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317 and D7S820. The Chueta population has remained isolated because intermarriage with non-Jews did not take place until the middle of this century, which has resulted in it being a small inbred community. The results indicate the existence of HW equilibrium for the Chueta and Balearic populations. No pair-wise correlation was observed between the nine markers. Consequently, they seem to comprise a suitable group of markers for population genetics purposes and for paternity and forensic testing.