Peritoneal tuberculosis (TB) is a rare disease among the general population that can be seen in patients with associated immunocompromised conditions such as diabetes mellitus, human immunodeficiency virus (HIV)-positive patients, patients with liver cirrhosis, patients on peritoneal dialysis, and patients on treatment with anti-tumor necrosis factor (TNF) agents. Patients who already have active pulmonary TB and who are not treated promptly can develop disseminated disease within the lungs or can affect extrapulmonary organ systems such as the nervous system, gastrointestinal system, or urinary system. It is unusual to see an otherwise healthy person develop peritoneal TB as a first-time diagnosis, without any previous exposure to TB or any immunocompromising condition.The diagnosis of this condition can be tricky as the clinical and radiological manifestations of this disease strongly mimic that of malignancy, such as ovarian cancer or peritoneal carcinomatosis. In the majority of cases, the first impression of malignancy is made while examining the radiological images of the abdomen, and only after obtaining the biopsy results, an unexpected diagnosis of peritoneal TB is established. Hence, it is an interesting and uncommon diagnosis, which should always be kept in mind while managing patients with an apparent gynecological malignancy.Here, we report a case of a 65-year-old female patient who presented with a history of abdominal pain and weight loss. Initial investigation with abdominal ultrasonography revealed ascites with multiple subcentimeter mesenteric lymphadenopathies. She also had an elevated cancer antigen 125 (CA-125), which further raised suspicion of gynecological malignancy. However, following the investigations, it was found that the actual diagnosis was an unexpected one.