Non-Hodgkin's lymphoma is the most frequent nonepithelial malignancy arising in the nose and paranasal sinuses. It is nonetheless, an uncommon neoplasm in this location. The authors describe 4 patients with non-Hodgkin's lymphoma arising in the nasal cavity, sinuses and nasopharynx. All were men. Most frequent symptom was nasal obstruction. Clinical stage were IIE to IV. The classification systems for non-Hodgkin's lymphoma have become increasingly elaborate during the past decade such as Rappaport, Lukes-Collins, Working formulation of National Cancer Institute systems. But these newer classifications have not been applied to a group of sinonasal lymphomas yet. So we tried to classify sinonasal lymphomas using various newer classification systems. We report our cases with a brief review of literatures.