Serum concentrations of paracetamol were followed after oral administration of the drug to 21 patients with liver cirrhosis, 4 patients with secondary liver cancer, and 15 hospitalized patients without clinical evidence of liver disease. The cirrhotic patients had 50 per cent longer half-lives of the drug. They also had significantly higher values of AUC during the first 360 minutes, in spite of almost identical means values of Cmax and tCmax. Significant differences in paracetamol elimination between cirrhotics with and without ascites, or between cirrhotic with and without porto-caval shunt could not be demonstrated.