We evaluate the prognostic significance of chronic liver diseases followed by diabetes mellitus in 40 patients by Child class, immunoreactive insulinemia (IRI), C peptide (CP) and pancreolaury-test (PLT) at 5 years. Death and hepatic insufficiency prevalence were significantly higher in cirrhotic diabetics, and in those diabetics with a lower insulin secretion (IRI, CP). Insulin hyposecretion (lower IRI, CP) was found in cirrhotic with abnormal PLT (below 20%). The onset of diabetes mellitus in liver cirrhosis has a bad prognosis when it is caused by decreased insulin secretion produced by chronic pancreatitis or pancreatic insufficiency.