The objective of this study was to investigate the prevalence of hepatic cysts by age and gender in patients with early autosomal-dominant polycystic kidney disease (ADPKD) and to determine whether hepatic cyst volume is related to renal and renal cyst volumes by using magnetic resonance imaging (MRI). A total of 230 patients with ADPKD (94 men and 136 women) who were aged 15 to 46 yr and had relatively preserved renal function were studied. MRI images of the kidney and liver were obtained to measure renal, renal cyst, and hepatic cyst volumes. These volume measurements and hepatic cyst prevalence were compared in all patients and in subgroups on the basis of gender and age (15 to 24, 25 to 34, and 35 to 46 yr). The overall prevalence of hepatic cysts was 83%; the prevalence was 58, 85, and 94% in the sequential age groups and 85% in women and 79% in men. The prevalence was related directly to renal volume (chi2 = 4.30, P = 0.04) and to renal cyst volume (chi2 = 5.59, P = 0.02). The total hepatic cyst volume was significantly greater in women than in men (a logarithmic transformation mean of 5.27 versus 1.94 ml; P = 0.003). The average hepatic cyst volume was 0.25, 5.75, and 22.78 ml in sequential age groups. Hepatic cysts are evident in 94% of patients who are older than 35 yr and in 55% of individuals who are younger than 25 yr. Hepatic cysts are more prevalent and larger in total cyst volume in women than in men. Hepatic cyst prevalence and aggregate total hepatic cyst volume increased with age.