The investigation was carried out in Pushkin region of Azerbaijan SSR. The coefficient of inbreeding was found to be 0,01142 in 2 typical villages; the frequency of consanguineaous marriage in both villages was 30+. The occurence of consanguineous marriage is explained by a little migration of the population, large families and a stability of marriage traditions. An increased frequency of parental consanguinities of sporadic schizophrenic patients in comparison with the average one was found. This indicates the determination of some cases by rare recessive genes.