The frequency and degree of the intima diffuse thickening (IDT) of heart coronary arteries from 186 autopsy cases--newborns and children of the first year of life of both sexes in the cities of Moscow, Frunze and Yakutsk, were studied. The higher incidence and higher degree of intensity is noted in Moscow as compared to Frunze and Yakutsk. Statistically significant differences are found between male infants in Moscow as compared to indigenous (p less than 0.001) and non-indigenous male infants in Frunze and Yakutsk; in female infants such differences (p less than 0.002) are found between those in Moscow on the one hand and indigenous female infants in Frunze and Yakutsk. In Frunze and Yakutsk the incidence and degree of intensity of IDT was somewhat higher in non-indigenous population of both sexes. The highest incidence and degree of intensity of IDT of coronary arteries were in children of both sexes whose mothers suffered from arterial hypertension.