PURPOSE: To evaluate the usefulness of spiral CT in predicting the depth of tumor invasion in patients with gastric cancer by comparing with histopathological finding. MATERIALS AND METHODS: We studied spiral CT scans of forty-eight patients, in whom gastric cancer was proven by gastrofibroscopic biopsy and surgery. After distending the stomach with 400ml tap water or effervescent granules, 100ml of contrast media was given intravenously at a rate of 3ml/sec. CT scanning was started at 45 sec after administration of the contrast material. Gastric tumors were subdivided into five types according to enhancing pattern from the inner layer of gastric wall to the outer layer. These pattern were correlated with histopathologic results. RESULT: The tumor masses were detected on CT scan in 10(77%) of 13 patients with early gastric cancer, while, the tumor masses were seen on CT scan in all patients with advanced gastric cancer. Of 9 patients with type 1 or type 2 enhancing pattern, early gastric cancer(T1) were proven in 7 patients(78%), serosal invasion (T3) in 2 patients(22%). In contrast, among 29 patients with type 4 and type 5, 22 patients(76%) were proven as serosal invasion(T3). Of 7 patients with type 3, 3 patients(43%) were proven as serosal invasion(T3), three(43%) as subserosal invasion(T2), one as early gastric cancer(T1). CONCLUSION: Analysis of morphological enhancing pattern on spiral CT is useful in predicting the depth of tumor invasion in patients with gastric cancer.