The peritoneum is one of the most common extrapulmonary sites of tuberculous infection, however due to variety of clinical presentation diagnostic challenge occurs. The nonspecific features of the disease can lead to diagnostic delay and development of complications. Especially in women who present with ascitis and elevated CA125 level can mimic malignancy. A 27-year-old, female was referred for evaluation of massive ascites, enlarged cervical lymph node, and low-grade fever. Primary she was worked up with ascites and was found that cancer marker CA 125 was elevated. Then she was operated by gynecologist with the presumed diagnosis of ovarian malignancy which wasn’t confirmed during operation. On examination: patient appeared ill, a single non-tender, fluctuant node in the right subclavicular region, distended abdomen with massive ascites, no signs of peritonitis. The rest of examination was unremarkable. Histological examination of peritoneum was confirmed TB. So, the diagnosis of tuberculous (TB) peritonitis was considered. After prescription of standard antituberculous treatment the patient condition improved, she was discharged from hospital on day 10th to continue treatment for 6 months. Conclusion:  Clinical diagnosis of peritoneal TB should be considered in a relatively young female with lymphocytic ascites without malignant cells. Initial diagnosis of TB would be beneficial not only to provide early treatment to the patient, but also averting the spread of the disease to others. A high index of suspicion is an impotent factor in early diagnosis. Early diagnosis and initiation of antituberculous therapy are essential to prevent morbidity and mortality. Most of the patients respond very well to standard antitubercular treatment.

Keywords: Extrapulmonary Tuberculosis, Ovarian cancer, Peritoneal Tuberculosis, Scrofula.