This study reports a case of female genital tuberculosis in a 46-year-old woman who presented to emergency department with abdominal pain and progressive abdominal distension. The patient was initially thought to have ovarian cancer based on clinical diagnosis and elevated cancer antigen-125 (CA-125) levels. Intra-operatively, no obvious ovarian tumor was encountered instead; disseminated creamy white patches on the uterus and left adnexa were seen. About 4500-mL straw-colored ascitic fluid and disseminated creamy white patches were also found on the bowels and omentum giving an impression of carcinomatosis. However, histopathology of the fallopian tube and ovary confirmed the diagnosis of female genital tuberculosis as the underlying cause. Female genital tuberculosis often mimics tumors in its clinical appearance and symptoms, leading to misdiagnosis and unnecessary treatment. The key to diagnosing female genital tuberculosis is being suspicious as it is challenging to diagnose through laboratory tests or radiology. The mainstay of treatment for female genital tuberculosis is a combination of four antituberculosis drugs. Consideration of female genital tuberculosis as a differential diagnosis in women presenting with symptoms mimicking reproductive tumors is highly recommended as highlighted in this case report.