Five cases of a rare malignant sinonasal tumour of neurofibromatous nature are described. The term neurogenic sarcoma (or malignant peripheral nerve sheath tumour) is advocated instead of malignant schwannoma. The clinicopathological features of this tumour are described, and the different diagnosis are discussed. The necessity of using immunohistochemistry in the diagnosis of sinonasal tumours of fibromatous nature is emphasized. The clinical management consists of radical surgery and adjuvant radiotherapy. Clinically there seems to be a high-grade and a low-grade type of sinonasal neurogenic sarcoma, however, this could not be distinguished histologically in the present series.