Radiotherapy (RT) or concurrent chemoradiation therapy (CCRT) is not only effective at patients' survival rates, but also produces undesirable late complications. The purpose of this study is to investigate the post-treatment late complications in nasopharyngeal carcinoma (NPC) patients, and to analyze the individual impact factors. We enrolled 188 newly diagnosed NPC patients who had received complete treatments and at least 3 years' follow-up between March 1984 and March 2010. Late complications were modified from the Toxicity Criteria of the Radiation Therapy Oncology Group and the European Organization for Research and Treatment of Cancer. Of 188 patients, 132 were male and 56 were female. Eighty-eight patients received CCRT and the other 100 patients received RT alone. The median follow-up duration was 7.34 years (range 3.30-26.54). Only 5.3% of patients reported no complication during post-treatment follow-up. The most common major and minor complications were osteoradionecrosis (10.1%) and xerostomia (56.4%), respectively. There was no impact factor for age, underlying disease, and cancer staging. However, there was a negative impact factor for xerostomia and limb numbness in the CCRT group compared with the RT group. Besides, re-radiation for recurrent patients could increase the risk of major complications. Fortunately, these major complications were reduced after the introduction of intensity-modulated radiotherapy in 2003. The improvement of treatment modality decreased the risk of major complications. Physicians should pay more attentions and improve patients' quality of life during follow-up.