A case of cystic dysplasia of the rete testis (CDRT) is reported. Nine months after right orchidopexy, a 10-year-old boy presented a palpable mass in the ipsilateral hemi-scrotum. Preoperative ultrasound showed a cystic lesion involving almost the whole testis. Radical orchidectomy was performed and at gross examination a hilar multiloculated cystic lesion was confirmed; microscopic examination showed cystic spaces lined by benign appearing monostratified epithelium with atrophy of the surrounding testicular parenchyma. These findings were consistent with the diagnosis of cystic dysplasia of the rete testis. Immunohistochemical investigation evidenced a pattern similar to that of a normal rete testis. Renal ultrasound and DTPA scintigraphy performed after pathological diagnosis documented the absence of the ipsilateral kidney. CDRT is a rare cause of scrotal swelling in the pediatric patient. When diagnosis is suspected, based on clinical and sonographic findings, conservative surgery may be considered.