Gastric cancer is the most common gastrointestinal malignancy in Korea. Identification and evaluation of gastric mass lesions and regional-distant metastases by abdominal CT scan are important for the treatment planning and prognostic implications of gastric cancer patients. Author reviewed CT scan of 61 cases of pathology-proven gastric cancer, retrospectively, for recent 20 months from July 1983 to Feb. 1985 at department of radiology, Korea University, Hae Wha Hospital. The results were as follows: 1. There were 50 cases of advanced adenocarcinoma, 8 cases of early gastric cancer, 2 cases of leiomyosarcoma, and 1 case of lymphoma in total 61 cases. 2. The sex ratio of male to female was 2:1. Age distribution was from 24 to 75 year lod and peak incidence was in 6th decade. 3. The most frequent site of involvement with gastric cancer was gastric antrum in 51%. 4. 48 of the 50 patients with advanced gastric adenocarcinoma(96%) had a wall thickness greater than 1cm, and all of cases of early gastric cancer had a wall thickness less than 1cm. Regional lymph node tumor infiltration was found in 100% of gastric wall thickness greater than 2.0cm, in 6.4% of cases of 1.5 to 2.0cm, in 50% of cases of 1.0 to 1.5cm, and 12.5% of cases of less than 1.0cm. 5. In a comparison of enlargement of regional lymph node by CT scan to tumor infiltration of regional lymph node by histology, sensitivity was 52%, specificity was 87%, and reliability was 66%. 6. The structures involved by distant metastases of these cases were the retroperitoneal lymph node in 15, liver in 8, and pancreas in 3. 7. The diagnostic accuracy of CT staging was considered about 68% by correlation of the surgical and histological findings. 8. The CT scan is one of the accurate and simple tool for evaluation of size, shape, extent, as well s distant metastases in the cases of gastric malignancies.