Thirty seven patients with Stage I yolk sac tumor of the testis were registered at the Instituto Nacional de Enfermedades Neoplasicas (I.N.E.N.), Lima-Peru from 1962 through 1980. Eighteen patients underwent retroperitoneal Lymph node dissection. The age incidence was 5 to 29 months except for two patients 50 and 84 months of age each. Bilateral retroperitoneal lymph node dissection was performed in seventeen patients; unilateral dissection was performed in one patient. In two patients both had one positive node at lymphadenectomy (2/18: 11%). Eleven patients (61.11%) are alive and with no evidence of disease in between 7 to 26 years post lymphadenectomy. Seven patients (38.89%) died: 4/18 (22.22%) because of progression of the disease and three patients because of no neoplastic cause. Nineteen patients did not have retroperitoneal lymph node dissection: seven patients (36.84%) are alive with no evidence of disease and 12 patients (63.16%) died: 8/19 (42.10%) because of progression of the disease and 4/19 (21%) with no neoplastic disease. In conclusion, patients with localized disease (Clinical Stage I) benefit from retroperitoneal lymph node dissection when compared to a similar group of patients not submitted to lymphadenectomy.