PURPOSE Testicular teratoma is a rare neoplasm affecting the pediatric population and has classically been reported to be the second most common testis tumor in children behind yolk sac tumors. Testicular teratomas are benign and partial orchiectomy may be considered. We describe our single institution experience with testicular teratoma and definitive treatment with testis preserving surgery. MATERIALS AND METHODS We reviewed the pathology records at our institution for all testicular and paratesticular tumors diagnosed between 1976 and November 2002 in males younger than 18 years. We specifically examined the prepubertal incidence of teratoma, including epidermoid cysts, and our experience with testis preserving surgery. Preoperative and postoperative ultrasonography images were used to calculate the atrophy index following surgery. Patients were contacted for long-term followup. RESULTS Of 77 primary testicular and paratesticular tumors 38 were diagnosed in prepubertal boys (age younger than 13 years) including 11 mature teratomas and 5 epidermoid cysts. Mean patient age at treatment was 34.4 months (range 4 months to 10 years). All boys presented with a painless scrotal mass, cystic foci within an intratesticular mass on ultrasound and a normal alpha-fetoprotein level. Of the 16 boys with benign teratomas 13 (81%) were treated with a testis sparing procedure. At a mean 7-year followup no patient has presented with recurrent tumor in the ipsilateral or contralateral testicle. Postoperative physical examination and scrotal ultrasound were obtained in 9 patients at a median followup of 10.2 months, and there was no evidence of testicular atrophy or persistent discomfort. CONCLUSIONS Unlike previously published series based on tumor registries, benign teratoma was the most common pediatric testicular tumor treated at our institution. Our single institution experience with testis preservation and long-term followup confirms the role and safety of this technique. Testis sparing surgery remains our technique of choice for testicular teratoma.