We present the case of a 1-year-old boy who had had a right scrotal enlargement for 9 months. He experienced a sudden onset of right scrotal enlargement and irritability at 3 months of age. No testis but hydrocele was identified at 5 months by sonography at another hospital. On admission, an elastic mass in the right scrotum measuring 3 cm  2 cm  2 cm was noted. Sonography showed a cystic, thick-walled mass, wherein no testis was identified. Magnetic resonance imaging failed to reveal his right testis along the descending route of the right testicle. During the operation, the mass was found to be cystic with a thick wall, and the cyst contained a yellowish clear fluid. The spermatic cord was connected to the mass and the junction between the two was constricted. The pathology of the cyst wall revealed atrophic testicular tissues, including stromal fibrosis and small tubules that were focally filled with small cuboidal cells. The atrophic cystic change in the testis in this case was considered to be due to previous testicular torsion. Late-stage cystic change after testicular torsion must be rare as a late presentation because it has never been reported in the literature.