In our hospital over the last 10 years a diagnosis of nodular regenerative hyperplasia was made for 13 patients. Sixty-nine percent of these patients had portal hypertension, representing 27% of all our patients with portal hypertension and a non-cirrhotic liver. Nodular regenerative hyperplasia was the second most frequent cause of portal hypertension in patients without cirrhosis. To make the diagnosis, a reticulin staining of a surgical biopsy is most helpful. However, the characteristic derangement of the liver architecture on histology may still be overlooked. In this study a suggestive relation was found between malignant disease (multiple myeloma, chronic myelogenous leukaemia, Leydig cell tumour and Hodgkin's disease), the use of cytotoxic or immunosuppressive drugs and nodular regenerative hyperplasia. Furthermore, a high rate of symptomatic nodular regenerative hyperplasia was observed in patients following kidney transplantation. Liver function abnormalities developed in these patients after a period ranging from 8 months to 3 years of immunosuppressive- or chemotherapy. These liver function abnormalities were, however, usually mild. Since hepatic encephalopathy is not likely to develop in these patients with nodular regenerative hyperplasia a decompressive shunt operation is a good alternative approach, if not the treatment of choice, for the prevention of recurrent variceal haemorrhage.