Two hundred and fifty-five mentally retarded women (cases) and their age-matched control women with no mental retardation (controls) requiring the assistance of a gynecological consultant were studied. Reasons for consultation, heights, weights, blood pressures, smoking histories, medications, gynecological findings and therapeutic measures recommended after examination were recorded. In comparison to the group of non-mentally retarded control women the group of mentally retarded women had no deliveries at all, the number of pregnancies was 118.3 times less (p < 0.001), abortion 20 times less (p < 0.01), gynecological laparotomies 4.3 times less (p < 0.05) and diagnostic curettages 25.7 times less often (p < 0.001), but the number of lynestrenol induced therapeutic amenorrhea (TA) 123 times more (p < 0.001), anticonvulsive drug therapy 91 times more (p < 0.001), polypharmacy 22 times more (p < 0.01) and virginal gynecological status 11.7 times more often (p < 0.001). Further, among the mentally retarded cases than non-mentally retarded controls, contraception was 58 times less (p < 0.05), not smoking 1.2 times (p < 0.001), the incidence of genital infections 2.9 times and tumors of all kind 4.6 times less common (p < 0.001). Of the present mentally retarded women 67.5% had at least once in their life received lynestrenol for TA. Autopsy confirmed arterial diseases occurred in two out of four mentally retarded patients aged 44 and 45 years, who were current lynestrenol users and died during the study period. Therapeutic amenorrhea exhibited a clinical picture of depressed pituitary gonadal axis.