Purpose: NPC is a malignant and invasive tumor with the incidence rate of 19/100,000per year in Zhongshan City, a prefecture city in southern China. Long-term survival analysis on intensity-modulated radiotherapy (IMRT)-based treatment in local prefecture-level hospitals have not been investigated. We aimed to evaluate the 5-year clinical outcomes and prognostic factors of NPC treated with IMRT in Zhongshan City People's Hospital (ZSPH), a prefecture-level hospital in South China. Patients and Methods: The number of 149 newly diagnosed non-metastatic NPC cases treated with IMRT were included from Zhongshan City People's Hospital between January 2010 and December 2011. The survival outcomes, treatment toxicities and prognostic factors were analyzed by Kaplan-Meier method and Cox proportional hazards model. Results: With a median follow-up period of 65 months for the cohort, the 5-year local recurrence-free survival (LRFS), regional recurrence-free survival (RRFS) and distant metastasis-free survival (DMFS) and overall survival (OS) were 86.80%, 94.80%, 86.10% and 80.50%, respectively. The 5-year OS rates were 100%, 95.2%, 87% and 67.2% for stage I, II, II and IVa-b, respectively (P=0.004). The 5-year LRFS rates were 97.2%, 96.0%, 90.4% and 72.0% for T1, T2, T3 and T4, respectively (P=0.001); the 5-year DMFS rates were 100% for T1, 96.8% for T2, 81.9% for T3 and 74.6% for T4 (P=0.022). A multivariate analysis revealed tumor stage as an independent prognostic factor for LRFS, DMFS and OS. No patients died from acute toxicities. Late toxicities were observed for 130 (87.2%) patients, and most late toxicities were graded I/II. Conclusion: NPC treatment effect in a prefecture-level hospital in South China was comparable to international results and toxicities were tolerable. Tumour stage was an independent prognostic factor for survival outcome. More NPC survival data from local and remote places are needed.