The authors analysed the CT findings in 75 cases diagnosed as gastric carcinoma by U.G.I.S. or endoscopy in a 3$frac{1}{2}$year period. The comparative analysis between CT findings and surgical pathologic findings was done in 55 cases who underwent surgery. 20 cases could not be operated upon because of distant metastasis. The gastric carcinoma was devided into 4stages according to the staging system of the American Joint Committee on Cancer. The CT findings were then compared and the following results noted: 1. The relationship with gastric wall thickening and penetration degree of tumor; no thickening(lesser than 1.0 cm) of 3 cases showed all of T1, 11 of localized thickening(1.0-1.5cm) showed 7 of T2, 38 of localized thickening(more than 1.5 cm) showed 37 of T3, and 3 of diffuse thickening showed all of T4a. 2. The accuracy of lymph node detection by CT scan; 1) Regional lymph node showed 86% in operative finding and 73% in pathologic. 2) Extragastric lymph node showed 87% in operati e finding and 89% in pathologic. 3) Retro-peritoneal lymph node showed 96% in operative finding and 95% in pathologic. ic. 3. In operated cases, there was one case of false positive distant metastasis and three false negative cases. 20 cases of non-operated cases showed distant metastasis such as liver, lung or kidney. 4. 55 cases were classified as stage I in 4 cases, II in 18, III in 23 and IV in 10 by pathologic findings, and I in 3, II in 24, III in 19 and IV in 9 by CT. The overall accuracy by CT staging is 75%. 5. Among a total of 75 cases, there were 46 operable cases by CT finding and 43 operable cases by pathologic staging. There were 29 inoperable cases by CT finding and 27 cases by pathologic staging. Therefore, there was a 93% overall accuracy by CT staging in terms of determination of operability. Therefore, there was a 93% overall accuracy by CT staging in terms of determination of operability. 6. The accuracy of adhesion into adjacemt structure by CT finding was 69%, c mpared with operable finding.