Purpose: It has generally been accepted that the most common primary testicular tumor in the pediatric population is yolk sac tumor. Recently, there have been some reports that teratoma is the most common tumor in this age group. The histopathological distribution and clinical behavior of primary pediatric testicular tumors from three hospitals were retrospectively reviewed. Materials and Methods: A retrospective review was performed on 30 pediatric patients, who had been treated for primary testicular tumors, at three hospitals. The records of the patients were reviewed with respect to age at diagnosis, affected sites, presentation, operation, pathology and prognosis. The mean age of the patients was 68.3 months (1-234). Results: The most common presentation was a painless scrotal mass (86.7%). In patients younger than 15 years, the most common testicular tumor was teratoma at one hospital and yolk sac tumor at the other two hospitals. Totally, the most common testicular tumor was teratoma (52%), followed by yolk sac tumor (40%). In 5 patients, aged 15-20 years, the pathological distribution of the testicular tumor was the same as that observed in adults. No patients had had a recurrence after a mean follow- up of 30.6 months (3-109). Conclusions: Our results suggest that the prognosis for children with testicular tumors is favorable. The most common primary prepubertal testis tumor is teratoma, followed by yolk sac tumor, although yolk sac tumor was the most common tumor at two of the hospitals in this study. A large prospective multi-center study will be required to determine the pathological distribution of pediatric testicular tumors.