Chronic pancreatitis appears to be increasing likely because increase in alcohol consumption and improved diagnostic tools. So the diabetes due to chronic pancreatitis is gaining importance. In order to obtain a better understanding of that particular secondary diabetes, 179 patients with chronic pancreatitis were studied from 1970 to 1981. 154 patients were male and 25 female. Average admission age was 45, ranging from 25 to 86. All the patients underwent medical therapy, based on diet, pancreatic enzymes, pain control. 99 of them underwent even to surgery. The follow-up is ranging from 6 months to 10 years: during this period 18 patients died, 41 went lost. 120 patients are still under observation. Diabetes was found in the family history of 27 patients (15%). At hospital admission 41 patients (23%) had high fasting glycemia, 23 of them even glycosuria. Other 74 showed diabetic oral glucose tolerance test. During the follow-up time 27 became clinically diabetic, 3 died because hyperosmolar coma and 8 had to be readmitted more than once because diabetic metabolic decompensation. Among the 120 patients at the moment under control, 66 (55%) show abnormal fasting glycemia, 10 developed high blood pressure, 12 inferior limbs vasculopathy with paresthesias and intermittent claudication, 2 myocardiosclerosis and atrial fibrillation, 1 myocardial infarction, 2 chronic nephropathy, 1 diabetic retinopathy. Whereas surgery or medic therapy may relieve chronic pancreatitis typical symptoms, they appear to be useless remedy against the under lying diabetes. As the time goes on more and more patients develop glucose intolerance, quite early became insulin-dependent, are disposed to severe diabetic metabolic decompensation and can show vascular, cardiac or renal complication.