We prospectively studied 512 consecutive women attending the antenatal clinic of the Rotunda Hospital of Dublin, Ireland, to assess the prevalence of gallstones among them and to describe the characteristics of those women found to be gallstone-positive (group 1), compared with the negative-control population (group 2). Real-time ultrasound scanning of the pelvic area was extended to the upper part of the abdomen. Cholelithiasis was detected in 23 patients. No substantial difference was found in parity of group 1 as compared with group 2. Also, early pregnancies, age at menarche and oral contraception did not have any significant difference between the two groups. However, we recorded a significantly higher prevalence of cholelithiasis in older women and in patients with dysmenorrhea. A positive trend was found in patients who had a history of previous breast-feeding and in women with a positive maternal history of symptomatic gallstones.