Prepubertal primary testicular tumors account for ∼1% of all pediatric solid tumors. We report a new case of prenatal diagnosis of juvenile-type granulosa cell tumor (JGCT). A fetal ultrasound performed at the 38th week of gestation for suspected nonvertex presentation identified a left multilocular septated cystic testicular mass, suggestive for JGCT. At birth, a painless left scrotal mass was detected. Ultrasound re-evaluation excluded torsion of the testis. Tumor markers and abdominal ultrasound were normal for age. Inguinal exploration revealed a cystic mass beneath the tunica albuginea that had replaced all the normal parenchyma. Since organ-sparing surgery was thus not feasible, an orchiectomy was performed and diagnosis of JGCT was confirmed. At 7-year follow-up, the child presented an uneventful outcome. Our case shows that neonatal JGCT, which has an intrauterine genesis, can be diagnosed prenatally by ultrasound in the last weeks of pregnancy.