The role of computed tomography (CT) scanning in a case of Yersinia enterocolitica (YE) enteritis mimicking acute appendicitis in a 34-year-old female patient with beta-thalassemia major is presented. Although the abdominal CT findings on admittance were indicative of acute appendicitis (enlargement of the appendix and thickening of its wall), making appendectomy a likely treatment option, a second CT scan 3 days later was diagnostic for infectious colitis (bowel wall thickening, ulcerations of the colonic mucosa, and fat stranding), and an unnecessary appendectomy was thus avoided. The diagnosis of YE colitis was later confirmed by serology tests.