Background. Tuberculous peritonitis is a rare event which can mimic advanced stage ovarian cancer. A pelvic mass and an elevated CA-125 is suggestive of an ovarian malignancy; however, benign conditions may be discovered, especially in the premenopausal patient. Case. A patient with a pelvic mass, ascites, and an elevated CA-125 underwent an exploratory laparotomy for presumed ovarian cancer. Final pathology revealed pelvic tuberculosis without any pulmonary involvement. Acid-fast bacilli were confirmed with polymerase chain reaction in the surgical specimen. Discussion. Pelvic tuberculosis is an uncommon gynecologic condition that presents with ascites, a pelvic mass, and fever. An elevated CA-125 is not specific for ovarian malignancy. (C) 2000 Academic Press.