Our report reviews the radiologic findings in 34 cases of duodenual malignant tumors with rare occurence seenat Severance Hospital between the year 1965 through 1979. Histologic diagnosis is predominantly adenocarcinoma incases of malignant tumors in the duodenum. Suprapapillary type showed polypoid mass with irregular mucosal ulcerincontrast to the annular constrictive lesions of infrapapillary. Irregular nodular filling defects or ulcer nearthe papillary area associated with dilatation of gall bladder or common bile duct, were main characteristicradiologic features of periampullary carcinoma. Leiomyosarcoma showed more prominant exoenteric growth rather thanitraluminal mass. But malignant lymphoma revealed relatively variable radiologic findings. The diffuse irregularmucosal thickening in the duodenum can be considered as radiologic manifestations of rare diseases such asExtramedullary Plasmocytoma and Histiocytic Medullary Recticulosis.