Alterations in carbohydrate metabolism are frequently observed in cirrhosis, and approximately 15% to 30% of patients have overt diabetes. In a retrospective and prospective study in cirrhosis, we analyzed the prognostic significance of diabetes, which was defined as the presence of hyperglycemia and overt glycosuria that in most cases required dietary restrictions or active treatment. The clinical records of all patients with cirrhosis admitted to our department for the period 1980 to 1985 were reviewed in 1985 and 1986, and surviving patients were prospectively followed up until December 1991. Final status could be obtained in 354 (98 with diabetes) of 382 eligible patients; 110 were alive at the end of follow-up. Prognostic factors were identified by Kaplan-Meier analysis, followed by Cox's stepwise regression. The model identified, in sequence, albumin, ascites, age, encephalopathy, bilirubin, diabetes, and platelets as prognostic factors. The larger mortality rate in patients with diabetes was not due to complications of diabetes but to an increased risk of hepatocellular failure. Diabetes was no longer a risk factor as a covariate in a subgroup of 271 patients when varices were added but was again significant when patients who died of gastrointestinal bleeding were excluded. The presence of diabetes, clinically detectable and often requiring adequate treatment, is a risk factor for long-term survival in cirrhosis.