An unusual hepatic disease developed in 3 patients with a well-functioning kidney graft 16-24 months after transplantation. Vague abdominal pain, increased bleeding tendency and edema were initial complaints, and hepato- or splenomegaly and ascites were found as well. Liver function tests were not or only mildly disturbed; hemolysis and pancytopenia were always present. Colloid uptake was absent at liver scintigraphy and the hepatic venous wedge pressure was increased. Esophageal varices were demonstrated. Liver biopsy showed extensive midzonal and pericentral sinusoidal dilatation. After discontinuation of azathioprine the symptoms and the extent of sinusoidal dilatation disappeared gradually, but after 1-3 years fibrosis or micronodular cirrhosis had developed and splenomegaly with hypersplenism remained. These observations strongly suggest an association between chronic use of azathioprine and the development of venous congestion of the liver with sinusoidal dilatation, eventually resulting in chronic liver disease.