Sinonasal undifferentiated carcinoma (SNUC) represents less than 1% of all malignancies. Most of the tumors are diagnosed at an advanced stage, when they have already invaded neighboring tissue structures. We describe the cases of 2 patients with a substantial intracerebral extension of SNUC who were treated at our institution. One was treated with surgery followed by chemoradiotherapy. The other was primarily treated with induction chemotherapy with a combination of docetaxel, cisplatin, and 5-fluorouracil followed by concurrent chemo- and radiotherapy. In view of the rarity of SNUC, no prospective clinical trials have been performed and a gold standard for treatment has not yet been established. Therefore, treatment recommendations are based on level IV evidence. These recommendations are diverse and controversial. In our 2 cases, the patient who was treated with induction chemotherapy had a better outcome. In cases of intracerebral extension, radical surgery is necessary and induction chemotherapy should be considered.