The clinical and pathologic features of four patients with malignant fibrous histiocytoma of the maxillary sinus were studied. All patients were male, with an age range of 43-71 years at the time of diagnosis. The main symptoms were pain in the facial region, swelling of the cheek and nasal bleeding. Pathologically, three patients were subclassified with the striform-pleomorphic type of malignant fibrous histiocytoma and one with the myxoid type. All patients were operated on and received various combinations of pre- and postoperative irradiation and intra-arterial chemotherapy given via the temporal artery. In the patient with the best prognosis, tumor extension within the maxillary sinus was minimal. Two patients developed local recurrences and died. None of the patients developed locoregional lymph node or systemic metastases.