Granulosa cell tumor (GCT) is a sex-cord neoplasm of the gonads classified into either juvenile (jGrCT) or adult type (aGrCT). It is commonly arising in ovaries but is much rarer in men, with only around 50 male cases previously reported in the literature. We report on a 54-year-old male patient with a right testicular GCT measuring 10.0×8.0×6.0 cm. The tumor was treated successfully with radical orchiectomy followed by computed tomography to assess lymph node involvement, and no further treatment was done. Pathological reports showed diffuse positivity for immunohistochemical stains, inhibin, vimentin, calretinin, and CD99. The clinical and histopathological features, treatment, and prognosis of aGrCT arising in the testicle of an adult male are also reviewed in this manuscript.