Testicular adrenal rest tumors (TARTs) are secondary to hypertrophy of adrenal rest cells in the rete testis in settings of hypersecretion of androgens. We present a case of congenital adrenal hyperplasia with TART with clues to the diagnosis on 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). To the best of our knowledge, this is the first reported case on the role of 18F-FDG PET/CT in TART.