Granulomatous appendicitis is a rare condition that accounts for less than 0.1~0.2% of all the cases of appendicitis. The great majority of cases are subacute or recurrent appendicitis and they are treated with interval appendectomy. The remaining causes include Yersinia infection, foreign body reaction, infection by mycobacteria, fungi or parasites, and Crohn's disease isolated to the appendix. Crohn's disease isolated to the appendix has several characteristics such as slow progression, a low recurrence rate and a good prognosis. Crohn's disease isolated to the appendix has recently been called "Idiopathic Granulomatous Appendicitis", and some authors have tried to distinguish it from Crohn's disease involving the appendix. We experienced a case of isolated appendiceal Crohn's disease in a 39-year-old woman and we report on it here along with a review of relevant literature.