Most gastric malignancies are advanced at the time of detection, so accurate diagnosis and staging are important for treatment planning and evaluation of the prognosis. Computed tomography is one of the most simple, rapid, non-invasive method of accurate diagnosis and staging of gastric malignancy. Authors anaysed significance of preoperative CT staging in 38 cases of pathologically confirmed gastric malignancies and the CT staging is compared with that of 20 cases who underwent surgery. RESULTS : 1. In a total of 18 cases who underwent surgery, resectability was 77.8% and false negative was 38.9%. 2. Causes of false negative interpretation are microinvasion to adjacent organs or metastatic micronodules, hidden regional lymphnode metastasis, misiterpretation to reactive hyperplasia of enlarged lymphnodes and indistint fat plane owing to severe emaciation. 3. Even a small localized mass without gastric wall thickening, there was extensive distant metastases, so accurate preoper tive CT staging would prevent unnecessar surgiacal exploration and will result in less complication, decreased mortality and expenses and allow more accurate treatment planning.