In fifteen cases of amebiasis masquerading as appendicitis, the important findings were nausea, vomiting, epigastric pain, pain in the right lower quadrant of the abdomen, fever, and leukocytosis. Amebiasis ought to be considered and appropriate studies carried out in differential diagnosis of cases in which symptoms indicate acute, subacute or "chronic" appendicitis. Depending on indications, the studies should include radiography with barium enema, sigmoidoscopy, complement fixation test, a minimum of nine stool examinations, a stool culture, and examination of purged stools unless this is contraindicated.