A series of 24 patients with cirrhosis have undergone mesentericocaval shunt operations for the relief of portal hypertension. Overall the results have been satisfactory. Four of the five patients treated as an emergency and 17 of the 19 who had the operation two to six weeks after haemorrhage had been controlled left hospital alive and well. Separation of the patients into three categories according to the findings of clinical and biochemical tests, however, showed that subsequent survival was satisfactory for patients in categories A and B but that all four patients in category C had died within one year after surgery. Assessment at three months showed that in three patients moderate hepatic encephalopathy had developed.Evidence that the shunt remains patent was shown by a low incidence of repeated gastrointestinal haemorrhage and a marked diminution in variceal size in 18 of the 19 cases examined serially. Radiographic techniques for confirming shunt patency were compared and cannulation of the graft via the femoral vein was found to provide a reliable and rapid means of assessment.