Objective To retrospectively analyze the efficacy and toxicity of intensity?modulated radiotherapy ( IMRT) alone and IMRT with concurrent chemotherapy ( CRT) in the treatment of early?stage nasopharyngeal carcinoma ( NPC) using pairwise group comparison. Methods A total of 98 patients with stage T1?2N1M0 NPC were treated with IMRT alone or CRT from 2009 to 2010, and 39 pairs out of them were selected for comparison of efficacy and toxicity. The survival rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. Results The 3?year follow?up rate was 95%. There were no significant differences in the 3?year overall survival ( OS ) , progression?free survival ( PFS ) , local recurrence?free survival ( LRFS ) , and distant metastasis?free survival ( DMFS ) rates between the IMRT alone group and the CRT group ( 97% vs. 95%, P=0?411;97% vs. 92%, P=0?301;97% vs. 97%, P=0?606;100% vs. 92%, P=0?082) . The incidence rates of leucopenia, anemia, and thrombocytopenia were significantly higher in the CRT group than in the IMRT alone group ( P=0?000;P=0?000;P=0?000 ) . There were no significant differences in the incidence rates of grade 3 oral mucositis and hearing loss between the IMRT alone group and the CRT group ( 26% vs. 23%, P= 0?093;41% vs. 62%, P= 0?100 ) . Conclusions CRT fails to increase the OS, PFS, and LRFS rates and reduce the DMFS rate in patients with stage T1?2 N1 NPC. Moreover, CRT results in higher incidence rates of hematotoxicity, grade 3 mucositis, and hearing loss than IMRT alone.