Sixty-six cases of acute appendicitis were proved by surgery during the period from May 1969 to May 1971. Thepresent study was designated to elucidate the findings of roentgen examination in acute appendicitis. The resultsobtained were summarized as follows; 1. Over 90 percent of cases of acute appendicitis showed significantradiographic findings. 2. Distention and fluid level in cecum and terminal ileum were disclosed approximately 75 percent of cases. It believe diagnostically significant in acute appendicitis. 3. About 10 percent of cases werefound extra-alimentary free air. 4. The roentgen finding of the fluid interposed between colonic contents and frank stripes in the right lower quadrant was another interesting finding to suspect acute appendicitis.