The hypothesis presented in this paper suggests that, at birth, the basic lesion of congenital hepatic fibrosis corresponds to ductal plate malformation of interlobular bile ducts, resulting from faulty development, i.e. disturbance in epithelio-mesenchymal inductive interactions. The immature bile ducts are subject to a progressive destructive cholangiopathy, resulting in a pattern of more or less advanced fetal type of biliary fibrosis. The destructive cholangiopathy may be of variable speed and duration in different patients. The renal lesions in autosomal recessive polycystic kidney disease, which is most often associated with congenital hepatic fibrosis, show a comparable pattern and evolution. The hypothesis that congenital hepatic fibrosis corresponds to a fetal type of biliary fibrosis would explain a number of disparate observations. According to this concept, congenital hepatic fibrosis does not correspond to a single clinical entity but to a broad, merging spectrum of conditions. All have in common that they represent some stage of biliary fibrosis, usually of the fetal type, rarely of the adult type, resulting from a slowly progressive, destructive cholangiopathy.