Small bowel tumors are rarely detected unless there is intestinal obstruction or bleeding. In the seven years 1982-1988, at Kosin Medical Center, 25 primary malignant small bowel tumors were studied radiographically with barium and/or computed tomograhy(CT). CT revealed gastrointestinal abnormalities in 20 patients. In ten, lesions were identified by upper G-I series, in 15 by small bowel series, and in addition, in 3 by colon enema. The most common malignant small bowel tumor was adenocarcinoma(N=15) and was next common lymphoma(N=7). On barium study, primary adenocarcinoma appeared as an irregular stricture(66.7%) and polypoid mass with intussusception was most prominent finding in lymphoma. Leiomyosarcoma appeared as an exophytic mass with excavation or ulceration. CT was found to be accurate in detecting wall thickening, complications and other associated findings. In conclusion, barium study was useful in the diagnosis of primary malignant small bowel tumor and CT was mor accurate in detecting secondary findings.