Background. Female genital tuberculosis is rare form of extrapulmonary TB. It may lead to delayed diagnosis because of the nonspecific features such as fever, abdominal distension, ascites, and weight loss. Here, we reported a case of prolonged fever and acute abdomen due to tubo-ovarian tuberculosis. Case Description. A female 22 years old came to ER with major complaint of right lower quadrant abdominal pain since 2 days. Patient has medical checkup history at the internal medicine clinic with complaint of prolonged fever for 2 months, decrease body weight 7 kg in 3 months, and abdominal tenderness. She has negative result for HIV, hepatitis, salmonella and TORCH work up. Physical examination in the ER found slight distended abdomen, Mc Burney sign (+), and subfebris. Laboratory result showed mild anemia (9,5), negative pregnancy test and elevated CRP and LDH . Abdominal doppler USG result free fluid intra-abdomen and cystic mass in the right pelvis impressive ovarian mass. CT scan with triple contrast confirmed there’re bilateral cystic mass with diameter ± 11 cm (right) and ± 7 cm (left) with feeding artery from a.ovarica refer to malignant ovarial cyst. The patient took laparotomy, and during operation found attachment of right tubo-ovarian with adnexa and active bleeding. The pathological expertises described necrotic tissue with granulomatous formation due to tuberculosis. Anti TB drugs was given for 9 month, and the patient showed clinical improvement with reduction of ovarian size. Conclusion. Tubo-ovarian tuberculosis should be considered in the differential diagnosis of lower quadrant pain with decrease body weight in young female who live in tuberculosis-endemic regions.