We report a case of a teratoma thrombus within the inferior vena cava subsequent to chemotherapy for embryonal carcinoma of the testis. A review of the literature indicates that intracaval metastases occur in approximately 1 per cent of the patients with bulky retroperitoneal disease. Seminoma and embryonal carcinoma have been identified previously within the inferior vena cava, and teratoma is now added to that list. The potential lethality of teratoma owing to local growth alone is underscored by its intracaval presence in this case. We recommend close inspection of the inferior vena cava at operation for bulky disease to exclude an intracaval thrombus, as well as complete excision of all residual masses following chemotherapy for testis cancer.