Physiologic melanin pigmentation (racial pigmentation) of the oral mucosa varies in prevalence among different races and ethnic groups. The purpose of this study was to investigate the prevalence of physiologic pigmentation in Israeli Jewish children of different ethnic origins. A total of 1,300 children, 6 to 10 years of age, was examined. Physiologic pigmentation was found in 13.5% of the population studied. Children of Eastern origin showed a significantly higher prevalence of pigmentation compared with Ashkenazi and Sephardic groups. Because melanin pigmentation can be enhanced by mechanical and chemical stimulation (smoking), this study may serve as a baseline for investigation of melanin pigmentation in various ethnic groups.