Sleep disturbance is frequently observed in cancer patients before, during and after oncology treatment. We explored the sleep features of patients before treatment, after induction chemotherapy, and after concurrent chemoradiotherapy for nasopharyngeal carcinoma (NPC). Ninety eligible patients diagnosed with NPC (stages III to IVc) and treated with induction chemotherapy plus concurrent chemoradiotherapy were included. The Pittsburgh Sleep Quality Index (PSQI) was applied to assess sleep before treatment, after induction chemotherapy, and after concurrent chemoradiotherapy. The median global PSQI scores in patients with NPC before treatment, after induction chemotherapy, and after concurrent chemoradiotherapy were 5, 6, and 10, respectively. The median scores of daytime dysfunction, sleep disturbance and habitual sleep efficiency were statistically significant at the pretreatment, after induction chemotherapy and after concurrent chemoradiotherapy timepoints (P < 0.049, P < 0.001 and P < 0.001, respectively). However, minimal changes were observed in all subscores after induction chemotherapy. Patients with poor sleep quality after induction chemotherapy were more prone to suffer worse sleep after concurrent chemoradiotherapy (OR = 12.6, 95%; CI = 2.4-67.3). Induction chemotherapy had less effect on the quality of sleep in NPC patients. Patients experienced a significant increase in sleep disturbance after concurrent chemoradiotherapy, particularly those with bad sleep after induction chemotherapy.Copyright © 2020 Elsevier Ltd. All rights reserved.