Fifty consecutive patients with gastric adenocarcinoma proved by means of biopsy underwent preoperative staging with endoscopic ultrasonography (US). Dynamic computed tomography (CT) of the chest and abdomen was performed before surgery in 33 of the patients. In all 50 patients, the TNM classification of the American Joint Committee on Cancer was used to compare the imaging findings with pathologic findings in specimens resected at surgery. When the depth of tumor penetration was evaluated, the findings at endoscopic US and those at pathologic examination were concordant in 46 of 50 patients (92%), and the findings at dynamic CT and those at pathologic examination, in 14 of 33 patients (42%) (P less than .00042). Evaluation of regional lymph node metastases showed a concordance of 78% with endoscopic US and 48% with dynamic CT (P less than .038). Overall determination of stage with both dynamic CT and endoscopic US showed a concordance of 73%, compared with a concordance of 45% for dynamic CT alone (P less than .028).