In acute pancreatitis the standard treatment is with antibiotics given prophylactically. Available studies indicate that the usefulness of such chemotherapy in the milder form of the disease (degree of severity I) has not yet been fully established. In the absence of contradictory results, prophylactic antibiotic treatment can, however, be recommended in severe pancreatitis (degrees II and III) and in those conditions induced by ethyl or of idiopathic origin. In all forms showing underlying biliary tract disease and in pancreatitis complicated by infection, antibiotic treatment should invariably be administered. Administration of broad-spectrum antibiotics which can be excreted via the bile duct, e.g. ampicillin or tetracycline, is preferable.