Abstract: Small cell neuroendocrine carcinoma (SNEC) of paranasal sinuses is uncommon. The histogenesis is notfully defined. Presence of neurosecretory granules and tumor cell affinity for silver stains are features suggestive of neu-roendocrine differentiation. It's also reported to be related to the existence of accessory salivary gland. Some researchessupport the hypothesis that the extrapulmonary SNEC might be derived from pluripotent stem cells. The clinical manifesta-tions are non-specific, mainly are rhinological syndrome and ophthalmic signs. Histology, immunocytochemistry and elec-tron microscopy are necessary in the diagnosis of SNEC of paranasal sinuses. It should be differentiated from poorly dif-ferentiated squamous carcinoma, melanoma, olfactory nerve blastoma and neurospongioma. There's no standard treatmentplan, and 2003 French protocol was a successful one. Reccurrence is frequent and the prognosis is poor. Combined thera-py can help improve the patient survival.