The mitochondrial DNA (mtDNA) of 332 individuals from Israel, including 270 Jews (originating from 7 communities) and 62 Arabs, was analyzed. Each mtDNA haplotype was determined by the fragment patterns of restriction enzymes HpaI, BamHI, HaeII, MspI (HpaII), and AvaII. The variability of the total sample and of each community was high. Of 40 different haplotypes, 20 were found more than once. Most haplotypes are typical of Caucasians, but African types were found among Ethiopian Jews and to a lesser extent among Arabs. The communities differed in their haplotypes: Chi-square tests among six communities showed significant differences for most pairwise comparisons and nonsignificant differences involving mainly the Moroccan Jews. In a genetic distance analysis only the Ethiopian Jews appeared to be distinguished from the other communities. According to a GST analysis, approximately 30% of the variation among the mtDNA restriction maps is attributable to differences between communities.