In the last fifteen years knowledge of lesions of the pancreas and skill in their surgical management have advanced extraordinarily, both because the syndrome of hyperinsulinism has become widely known and because surgeons in constantly increasing numbers have carried out operative procedures on the pancreas. Surgical treatment of the pancreas consequently has assumed for the general surgeon sufficient importance to make a review of the subject distinctly worth while. From Jan. 1, 1935 to Dec. 31, 1939, inclusive, at the Mayo Clinic, 255 operations were performed for lesions of the pancreas. This number means approximately that of every 1,500 patients registered in that period 1 patient was operated on for disease of the pancreas. When one recognizes that in the same period 4,437 operations were performed on the gallbladder for cholecystitis, acute or chronic, and 1,488 operations on the bile ducts, one gains a clearer idea of the frequency with