Background: For elderly patients with locally advanced head and neck squamous cell carcinoma (HNSCC), the role of postoperative concurrent chemotherapy was controversial since the intolerable toxicities and increased acute mortality, thus, radiotherapy alone was recommended. Aimed to seek out a feasible regimen for concurrent treatment, we evaluated the feasibility and quality of life of postoperative concurrent radiotherapy and toripalimab (anti-PD-1 antibody) in elderly HNSCC patients. Methods: The IMPORT trial was an investigator-initiated, multicentre, open-label, parallel-group, phase 2, randomized study. Patients were enrolled at 3 hospitals in China. We randomly assigned (1:1) patients aged＞65 years, with ECOG Performance Status(PS) of 0–2, and with postoperative Stage III-IV (AJCC 8th Staging system) HNSCC to concurrent radiotherapy (60-66Gy) and toripalimab (240mg on D0, D21 and D42)(RT+PD-1 group) or radiotherapy alone(RT group). Following stratification by PS(0-1 vs 2) and pathological adverse features (extranodal extension or positive margin vs others), patients were randomly assigned using a computer-generated randomization list. Acute toxicities were reported. Quality of life were evaluated by EORTC QLQ-C30 and QLQ-H&N35 at baseline, week3, week6 and 1 month after radiotherapy, and the standard scores were compared between groups by linear mixed-effects models. Results: Between September 2020 and December 2021, 38 patients randomly assigned(19 per group). The median age were 70 years (range 66-81) for the RT+PD-1 group and 73 years (range 67-78 years) for RT group. 16 (84.2%) patients in the RT+PD-1 group and 15 (78.9%) patients in the RT group complete the planed radiation dose. In the RT+PD-1 group, 13 (68.4%) patients completed 3 cycles of toripalimab, 3 (15.8%) patients completed 2 cycles due to adverse events and 3 (15.8%) patients declined toripalimab; The most common adverse events of grade 3-5 was oral mucositis (55.6% vs 58.8%) and lymphocyte count decreased(61.1% and 41.2%) in RT+PD-1 group and RT group. In the RT+PD-1 group, only 1 patients experienced grade 3 immune-related enteritis. As to the quality of life scores evaluated by QLQ-C30, no difference was found in standard score of global health status, as well as in most functional scales including: physical, emotion, cognitive and social, except for role functioning (p = 0.045). As to the symptom scale scores evaluated by QLQ-H&N35, no difference was found in standard score of pain, swallowing, dry mouth, opening mouth, and stick saliva, except for speech problem (p = 0.032). Conclusions: For elderly patients with locally advanced HNSCC, postoperative concurrent radiotherapy and toripalimab was safe and feasible. Concurrent toripalimab did not worsen quality of life scores in the majority of cases. Clinical trial information: NCT04523883.