A 37-year-old woman was diagnosed with acute brucellosis. Despite appropriate antimicrobial therapy, high fever persisted. A contrast enhanced CT scan of the abdomen and pelvis revealed a left ovarian dermoid cyst. On the first postoperative day after left ovariectomy and right ovarian cystectomy were performed, the patient defervesced abruptly and continued to be completely afebrile. Cultures from bone marrow and dermoid cyst grew Brucella melitensis. The observation of a Brucella-infected ovarian dermoid cyst, which has not been previously reported, illustrates the importance of localized brucellosis as a cause of persistent infection despite appropriate antimicrobial therapy.