Based on the findings of 206 examinations, the authors advance their opinion of the role of X-ray computed tomography (XRCT) in the diagnosis of gastric cancer. The authors think that if their developed procedure for X-ray computed tomography based on the use of usual air as the only contrast agent by measuring it out in doses and administering into the gastric at CT scanning, which is called pneumoroentgenocomputered tomography (PRCT), is employed, it, preserving all the traditional, already known, advances of XRCT additionally yields highly valuable information on a direct damage to the gastric wall itself. The findings suggest that PRCT is especially effective in intramurally growing gastric cancers, the so-called squamous carcinomas, which are hardly differentiated for diagnosis and which are most common. Noteworthy is the fact that in seemingly unquestionable exophytic gastric cancer, detecting intramural tumorous infiltration adjacent to the exophyte, PRCT thus provides evidence that the exophyte revealed is the peculiar top of an iceberg, whose base shows a significant exophytic gastric carcinoma.