Investigation of 9,411 school children, 6 to 10 years of age, showed an increased prevalence of bacteriuria in enuretic and/or dysuric girls. In contrast, the prevalence of proteinuria was not found to be significantly higher in enuretic or dysuric children nor was bacteriuria more prevalent in enuretic or dysuric boys. A higher prevalence for nocturnal enuresis in boys and in children from large families was confirmed. In addition, a statistically significant correlation was also observed for prevalence of bed-wetting with ethnic group for girls and with mother's education for boys, but not with the other sociocultural factors investigated.