An 87-year-old woman who had had a lower abdominal mass for 32 years underwent a laparotomy. Surgery revealed a 21-cm left ovarian dermoid cyst with torsion. Pathologic examination showed a hemorrhagic infarct due to torsion, mucinous cystadenoma and tuberculosis within the tumor. Tuberculosis was also found in the endometrium, both ovaries, oviducts and omentum. The patient's recovery was uneventful after surgery and medical treatment. The clinical manifestations of tuberculosis can vary widely. Tuberculosis of an ovarian dermoid cyst may be silent for a long period of time unless other complications occur.