Objective To study the diagnosis,treatment and prognosis of sinonasal neuroendocrine carcinoma.Methods The clinical data of 11 cases with sinonasal neuroendocrine carcinoma treated in Zhejiang Cancer Hospital from 1998 to 2010 were analyzed retrospectively.Ten cases were small cell type and one case was atypical carcinoid.Two cases were Kadish stage A,six cases were Kadish stage B and three cases were Kadish stage C.One case was treated by only operation,one case by only radiotherapy,one case by only chemotherapy,two cases by radiotherapy and chemotherapy,and six cases by combined treatment(surgery followed by radiotherapy and chemotherapy).Results All cases were followed up for 2 months up to 12 years.Of six cases by combined treatment two cases died in 3 years and in 4 years after treatment respectively,three cases survived tumor-free for 12,8 and 8 years and one case was still in treatment.Of other five cases,four cases died in 12 months and one case died in 18 months after treatment.Conclusions There's no standard treatment plan.Combined treatment based on surgery should be adopted to nasal neuroendocrine carcinoma.Recurrence is common and the prognosis is poor.The key to improving the survival rate of the disease is early accurate diagnosis and combined treatment.