Thirty one cases of malignant tumours of the maxillary sinus presenting to the Department of Otolaryngology, Universiti Kebangsaan Malaysia over a four year period from 1982 to 1986 are reviewed. 18 cases (58.1%) were squamous cell carcinoma while seven cases (22.5%) were Non-Hodgkin's lymphoma. There were four cases (12.0%) of adenoid cystic carcinoma while in two cases (6.5%) the tumours were undifferentiated. Presentation was generally late. Nasal obstruction, facial swelling and epistaxis were the main presenting symptoms. Nasal involvement was found in 61.3% of cases, while 51.6% had involvement of the palate as well. Metastasis to the cervical lymph node were uncommon (6.5%). Surgery and radiotherapy with or without chemotherapy were the main modes of treatment in the management of malignant tumours of the maxillary sinus.