Diabetes mellitus (DM) in chronic pancreatitis (ChP) is considered a unique clinical and metabolic unit. Compared to type I DM it has many different properties: glycemic lability, more frequent hypoglycaemic episodes, and minimum incidence of ketoacidosis. The need of insulin administration to achieve satisfying diabetes mellitus compensation is significantly lower and response of peripheral tissues to endogenous and exogenous insulin significantly higher compared to type I diabetics. These clinical differences result from decreased but always preserved insulin secretion, decreased glucagon production, impaired external pancreatic secretion, and also excessive alcohol use or insufficient or irregular food intake of the patients. Secondary DM in ChP is accompanied by chronic, microangiopathic and neuropathic complications analogous to other DM types. Nonpharmacological treatment measurements of the first choice are elimination of alcohol, sufficient and adequate nutrition, and simultaneous treatment of impaired exocrinal secretion. A pharmacology treatment is insulin therapy! It is a substitution treatment for insulin deficiency. Insulin doses must be chosen very carefully because of the risk of hypoglycaemia. The most frequent cause of secondary diabetes mellitus in patients with pancreatic diseases in Europe is chronic alcoholic pancreatitis and in tropical countries and India non-alcoholic tropical calcific pancreatitis (TCP).

        Key words: Chronic pancreatitis - Secondary diabetes mellitus