Objective To analyze the prognostic impact of degree of bone metastasis in patients with nasopharyngeal carcinoma (NPC) after radiochemotherapy.Methods A retrospective analysis was performed on the prognosis of 109 NPC patients who had bone metastases after radiochemotherapy in Nanfang Hospital from June 1997 to December 2007.The Kaplan-Meier method was used to calculate survival rates; the log-rank test was used for univariate prognostic analysis; the Cox regression model was used for multivariate prognostic analysis.Results The 5-year follow-up rate was 97.2％.The 1-,2-,3-,and 5-year overall survival rates for all patients were 67.9％,48.6％,32.9％,and 17.4％,respectively.The 1-,2-,3-,and 5-year survival rates for the 43 patients with not more than 3 bone metastases and the 66 patients with more than 3 bone metastases were 90.7％ vs.53.0％,81.4％ vs.27.3％,72.1％ vs.6.2％,and 34.9％ vs.4.2％,respectively (P=0.000).In the patients with more than 3 bone metastases,the 1-,2-,3-,and 5-year survival rates for those with and without other metastatic sites were 56.5％ vs.72.1％,21.7％ vs.30.2％,3.1％ vs.13.0％,and 0.0％ vs.6.5％,respectively (P=0.866).The multivariate analysis showed that more than 3 bone metastases were an adverse prognostic factor in the patients (P =0.000).Conclusions The number of bone metastases is an important prognostic factor in NPC patients after radiochemotherapy.Patients with not more than 3 bone metastases have better survival than those with more than 3 bone metastases,and aggressive treatment should be considered.In addition,the staging system of NPC needs to be improved.