OBJECTIVE To assess the accuracy of spiral CT scan in the preoperative staging of gastric carcinoma by comparing it with surgical/pathological staging. METHODS Twenty-eight patients with gastric carcinoma who underwent both preoperative CT scan and surgery were retrospectively studied for TNM classification. All CT scans were reviewed for tumor location, gastric wall thickness, tumor extension, N1 and N2 nodal involvement, and metastases to the liver, peritoneum and lung. RESULTS Spiral CT staging was correct in 20 of 28 patients (71.4%). The preoperative CT scan had 96.1% sensitivity, 100% specificity and 96.4% accuracy for evaluating serosal invasion. The sensitivity, specificity and accuracy for assessing pathologic lymph node involvement were 73.1, 50.0 and 84.2 percent, respectively. In the present study, peritoneal metastasis could not be identified by CT but CT had 100% sensitivity for evaluating hepatic metastases. CONCLUSIONS Spiral CT is a useful modality for preoperative staging of gastric carcinoma with high accuracy for evaluating serosal invasion and hepatic metastases.