We report on the case of a 24-year-old white man with a history of chronic leukemia treated with unrelated bone marrow transplantation and chemotherapy who was correctly diagnosed with appendicitis rather than typhlitis. The approach to diagnosing an acute abdomen in the leukemic patient is discussed, with particular focus on appendicitis vs. typhlitis. A focused CT scan proved to be instrumental in making the correct diagnosis of appendicitis in our patient. The literature on this topic for the past 30 years is reviewed. The purpose of our report is to demonstrate that despite the recent trend toward diagnosing RLQ pain as typhlitis which requires medical management, there are still instances where it 'really is' appendicitis. Appendicitis, therefore, must always be ruled out in the leukemic patient.