Radiologic study of patients continues to be of major importance in the detection of gastric malignant neoplasms and often provides the stimulus for further diagnostic procedures. The conventional roentgenographic procedure for this disease comprises a careful fluoroscopic examination of gastric peristalsis and distensibility, and views obtained with graded compression, mucosal relief, double-contrast technique, and barium filling. No single method has the ability to disclose all pathognomonic signs of a gastric tumor. Pharmacologic motor inhibitors or stimulators may be used to aid study of peristalsis. The usefulness of peritoneography, parietography and arteriography in the diagnosis of gastric carcinoma is also examined. Diagnosis of early gastric carcinoma remains a radiologic challenge and the Japanese classification system is recommended. Perhaps the disease could be detected earlier, in countries with low or moderate incidence and without the benefit of regional screeing centers, if subtile roentgenographic techniques were applied to patients with conditions known to be associated with high risk of gastric carcinoma. The differential diagnosis of lesions which simulate gastric carcinoma is extensive and is briefly reviewed.