Approximately 2 billion people, which is about one third of the world's population, are infected with tuberculosis (TB). Around 10% of infected people will develop active TB at one point in their lifetime. We present a rare case of a 68-year-old male who presented to the emergency department with a 2-week progressive dyspnea. In addition, the patient complained of generalized weakness, subjective fevers, and abdominal pain in the right upper quadrant. Ascites was noted on physical exam, and the patient underwent a diagnostic paracentesis with initial workup that was unrevealing for underlying etiology. Abdominal computed tomography was done, which revealed peritoneal carcinomatosis. He underwent omental biopsy which showed necrotizing granulomatous inflammation with rare acid-fast bacilli. Repeat biopsy was culture positive for mycobacterium tuberculosis complex. The patient was started on rifampin, isoniazid, pyrazinamide, and ethambutol with improvement of his symptoms days after treatment was started. This case demonstrates how the diagnosis of peritoneal tuberculosis can be elusive. Physicians must be aware of this disease and its behavior in high risk patients, also of the current diagnostic limitations.