The development of sarcomatous component (SC) in testicular germ cell tumor (GCT) is an uncommon phenomenon. We searched our surgical pathology files from 1985 to 2007 and identified 33 cases of testicular GCTs with SC. The average age of patients was 31 years. All patients underwent radical orchiectomy, which demonstrated a GCT in all patients except for 3 patients who had received neoadjuvant chemotherapy. All testicular GCTs contained a teratomatous component. The GCTs were pure teratomas in 3 cases, and were mixed GCTs in the other cases. The SC was observed in primary testicular tumor (n=19), in metastasis (n=11), or in both primary testicular tumor and metastasis (n=3). The average percentage of the SC in the primary testicular GCT was 32% (range: 5% to 99%). The most common histologic type of SC was rhabdomyosarcoma (n=24), followed by high-grade unclassified sarcoma (n=5), rhabdomyosarcoma admixed with high-grade unclassified sarcoma (n=2), angiosarcoma (n=1), and low-grade myxoid sarcoma (n=1). Clinical follow-up information was available for 27 patients. Of the 13 patients whose SC was limited to the testicular GCT, 2 patients died of GCT not otherwise specified at 37 and 68 months, respectively; and 11 patients were free of disease at a mean of 46 months. Of the 14 patients with a SC in the metastasis, 7 patients died of GCT not otherwise specified at a mean of 95 months, and 7 patients were free of disease at a mean of 104 months. These results suggest that patients with a SC confined to the primary testicular GCT may not have a higher risk of mortality than those at a comparable stage without a SC. However, patients with a SC in the metastasis have an increased risk of mortality.