This paper reviews the complications that arose after 68 276 percutaneous liver biopsies performed from 1973 to 1983. The complications are analyzed in relation to the underlying liver disease and to the type of needle used. Death was infrequent (9/100 000); it was always due to haemoperitoneum and occurred only in patients with malignant diseases or cirrhosis. Complications were less frequent in AVH (44/100 000) than in other liver diseases (from 125 to 278/100 000). Death, serious haemorrhagic complications, pneumothorax and biliary peritonitis were more frequent after biopsy with the Trucut needle than after biopsy with Menghini's needle (3/1000 against 1/1000). Sixty-one percent of complications were discovered within two hours of biopsy and 96% within one day. The data indicate a post biopsy observation period of at least 24 hours. The day-case procedure should be reserved for patients not presenting liver tumour or cirrhosis.