A retrospective analysis of patients with pathologic stage I nonseminomatous germinal testis tumors treated with orchidectomy and retroperitoneal lymphadenectomy was done in an attempt to define the relapse pattern and to eventually identify risk factors predisposing to tumor recurrence. Of 102 patients, 91 (89.2%) remain disease free with a median follow-up of greater than 5 years (range 3-10 years), and 11 (10.8%) suffered relapse 3-35 months after lymphadenectomy (median free interval 6 months). 9 of 11 patients developed primarily intrathoracic recurrences. The tumor was so rapidly progressing at relapse, that it was diagnosed when clinically advanced in 7 of 11 cases. Nevertheless, 8 of 11 patients were salvaged with effective available chemotherapy and resection of residual disease. Only scrotal violation showed a significant increased risk of tumor recurrence (5 of 24 cases, versus 6 of 78 who had inguinal orchidectomy, p less than 0.05). We recommend a very close follow-up for all patients with pathologically assessed stage I nonseminomatous germinal testis tumors during the first 3 years following orchidectomy and retroperitoneal lymphadenectomy. With early recognition of relapse, an approximately 100% cure rate will be achieved with effective available chemotherapy.