Glucagonomas are rare pancreatic tumors of islet ahpha-2 cells. Less than 430 cases have been reported worldwide and 210 cases are malignant tumors. In generally, the tumors typically present with a characteristic constellation of symptoms including necrolytic migratory erythema of the skin, weight loss, non-insulin-dependent diabetes mellitus, anemia, cheliosis, stomatitis, and an increased thrombotic tendency. Since pancreatic glucagonomas are predominantly located in the tail and findings of radiographic or sonographic examination can remain unspecific, patients often present already metastasis when diagnosis is first established, and can be difficult to differentiate from the other pancreatic tumors. We report the case of a 59-year-old woman with an malignant glucagonoma of the pancreas infiltrating already the spleen and presenting metastatic lesion in perirenal lymph nodes, and that the tumor was not assocated with the characteristic skin rash. The pateint with a past history of a diabetes mellitus and hypertension for 9 years was admitted with cramp-like left lower abdominal pain, watery diarrhea, and nausea. A solid tumor of tail of the pancreas revealed by ultrasonography and abdominal computed tomography and distal pancreatectomy, radical nephrectomy, and splenectomy were performed. Immunohistochemial examination of the tumor did show glucagon-reactive tissue and electron microscopy revealed many secretory granules, 180 to 300 nm in diameter in granulated cells. After pancreatic tumor resection, the patient had normalization of plasma glucagon and blood sugar.