Primary endodermal sinus tumor (yolk sac tumor) of the mediastinum is a very rare extragonadal germ-cell neoplasm. Most patients are young and male. Since initial description of the endodermal sinus tumor in 1959, this neoplasm has been found more and more frequently. alpha-Fetoprotein is an important tumor marker. The treatment consists of multimodal therapy. A combined approach with chemotherapy followed by surgical resection of residual tumor seems to be the optimal management of this tumor. Even a palliative surgical resection in advanced tumors is indicated. We describe the case of a patient with an advanced yolk sac tumor that was refractory to chemotherapy. This patient was treated by palliative surgical resection.