A 76 years old male presented with complaints of fever, weight loss and anorexia for three months and increased frequency and urgency of urine for 20 days. Physical examination of abdomen showed a lump in right paraumblical region and extending up to inguinal and hypogastrium on right side. Postero-anterior view of chest radiograph was normal. Ultrasound and Computed tomography (CT) of abdomen revealed a giant exophytic right renal cortical cyst of 9.84x9.70 cm (volume 336 mL) size arising from lower pole. Ultrasound guided aspiration of the cystic lesion revealed yellowish coloured, purulent pus of about 280 mL. Ziehl-Neelsen staining and PCR tests of the pus was positive for Mycobacterium tuberculosis. Gram's staining and pus culture was negative for other microorganisms. Patient responded to anti-tubercular treatment and finally considered as primary tubercular giant exophytic renal cortical cyst. To our knowledge, this common entity is an extremely rare manifestation.