Review of the 55 reported cases of glucagon-producing tumors reveals that a distinctive clinical syndrome consisting of diabetes, a peculiar dermatitis termed necrolytic migratory erythema, weight loss and an increased tendency for thrombosis is associated with these neoplasms. Normochromic normocytic anemia, hypocholesterolemia, hypoproteinemia and generalized hypoaminoacidemia are frequent laboratory findings. Definitive diagnosis of a glucagonoma requires elevation of the fasting serum glucagon level. Selective arteriography of the pancreas has been the best method for localizing these neoplasms preoperatively, but the noninvasive technics of ultrasound and CAT scanning can also be helpful. When the tumor is benign, complete surgical excision can completely reverse all the clinical manifestations of the glucagonoma syndrome and result in lasting cure. Since, however, approximately three-fourths of these tumors are malignant, palliative therapy is frequently required. Cytoreductive surgery can decrease the amount of hormone-producing tissue and can improve or even temporarily reverse the clinical symptomatology. For disseminated disease, chemotherapy is necessary. The best results have been obtained with DTIC although streptozotocin has also been used.