The clinical, radiological and hepatic histological features of 51 patients with hepatobiliary fibropolycystic disease were reviewed. Many of the patients had more than one of the diseases; the combination of both congenital hepatic fibrosis (CHF) and Caroli's disease was most striking. Twelve patients with CHF (50% male) presented at 6 +/- 2 years of age (mean +/- SEM) with hepatosplenomegaly or variceal bleeding. Their main problems were recurrent variceal bleeds and renal disease. Polycystic kidneys and renal stones were present in 79% and chronic renal failure in 30%. Six of the 8 patients with Caroli's disease were male (75%) and presented later (aged 37 +/- 8 years) with hepatomegaly or cholangitis. Recurrent cholangitis developed in most (7/8) and 2 had polycystic kidneys. Twelve patients had a combination of CHF and Caroli's disease presenting with hepatosplenomegaly, bleeding or cholangitis. As in Caroli's disease, most (83%) were male, but the age of presentation (15 +/- 4 years), and the incidence of polycystic kidneys (42%) and renal failure (8%) was intermediate between CHF and Caroli's disease. In these patients, bleeds always predated cholangitis. Histologically, acute cholangitis was superimposed on the changes of CHF. Adult polycystic liver disease (10 patients) presented later (43 +/- 3 years) in females (90%) with pain, a mass or incidentally; polycystic kidneys were present in 33%. Microhamartomas (10 patients), which were usually incidental findings, were diagnosed latest (50 +/- 6 years). Three choledochal cysts were seen. The hazard of cancer in these diseases was reflected by 2 bile duct cancers and 1 pancreatic cancer (incidence 6%). This study has confirmed that hepatobiliary fibropolycystic diseases form part of a family and are often associated together. However, the diseases are of greatly differing severity and the prognosis in an individual patient is determined by the fibropolycystic diseases present.