Extrarenal cysts occur in patients with autosomal dominant polycystic kidney disease (ADPKD) most frequently in the liver. Ovarian cysts have been reported in women with ADPKD, but their frequency has not been determined. Therefore, we analyzed the historical data in our database of 337 women with ADPKD and 199 of their unaffected female family members (NADPKD). In addition, we prospectively studied 25 nonpregnant, premenopausal women with ADPKD and 25 nonpregnant, premenopausal, age-matched control women recruited from the general population to assess the occurrence of ovarian cysts. No women in either the control or ADPKD groups were receiving exogenous estrogen or progesterone. All women underwent sonographic examination using a 5- or 7.5-MHz vaginal probe. A normal ovarian follicle was defined as a fluid-filled structure less than 2 cm in average diameter, and an ovarian cyst as one of 2 cm or greater. From the historical data, 28% of the women with ADPKD gave a history of ovarian cysts compared with 18% of the NADPKD women (P < 0.05). In the prospective study, the mean age of the women with ADPKD was not different from that of the control women (40.9 +/- 1.2 v 39.3 +/- 1.2 years; P = not significant [NS]). There was no difference in frequency of normal follicles found in women with ADPKD or controls (80% v 96%; P = NS), nor was there a difference in the frequency of ovarian cysts found in women with ADPKD or controls (12% v 12%; P = NS). There was no difference in the calculated ovarian volumes between the women with ADPKD and controls (9.9 +/- 2. 5 v 7.2 +/- 1.2 cm3). Among the women with ADPKD, there was no correlation between mean ovarian volume and mean renal volume, nor was there a significant relationship between the occurrence of hepatic cystic disease and ovarian cysts. Therefore, a prospective imaging study suggests that ovarian cysts have no increased frequency in women with ADPKD compared with women in the general population.