AIM: A recently published study reported markedly increased risk of cryptorchidism among boys whose mothers had an average gestational alcohol intake of five or more drinks per week. The aim of this study is to follow up on this finding by estimating the association between prenatal alcohol exposure and persistent cryptorchidism. METHODS: We used prospectively collected information on prenatal exposures and obstetric information on the birth of 5716 boys, collected from 1984 to 1987. During the 16-19 years of follow-up in a nationwide patient register, 270 cases of cryptorchidism were diagnosed and 185 of these boys underwent orchiopexy. RESULTS: No positive association between the mothers' average weekly alcohol consumption and persistent cryptorchidism was observed. Binge drinking was nonsignificantly associated with an excess risk of orchiopexy (adjusted RR = 1.4; 95% CI 0.9-2.1), but not with having a diagnosis of cryptorchidism without orchiopexy. CONCLUSIONS: Mothers' average weekly alcohol intake was not associated with persistent cryptorchidism, but binge drinking may be a risk factor.