Unlinked autosomal microsatellites in six Jewish and two nonJewish populations were genotyped, and the relationships among these populations were explored. Based on considerations of clustering, pairwise population differentiation, and genetic distance, we found that the Libyan Jewish group retains genetic signatures distinguishable from those of the other populations, in agreement with some historical records on the relative isolation of this community. Our methods also identified evidence of some similarity between Ethiopian and Yemenite Jews, reflecting possible migration in the Red Sea region. We suggest that highresolution statistical methods that use individual multilocus genotypes may make it practical to distinguish related populations of extremely recent common ancestry.