Abu Ghosh is an Israeli Moslem Arab village located 11 km west of Jerusalem. Its population of about 2,200 has a common ancestry and is highly inbred. Blood pressures, weights, heights and other pertinent data were recorded for 1,881 (93.3%) of 2,017 subjects aged two years and over who were available for study. Mean blood pressures in children up to the age of 15 years were similar to those reported elsewhere. Among adults, the prevalence of hypertension, especially diastolic hypertension, was high. The relative effects of genes and environment on familial similarity in blood pressures are discussed.