This current study explored the relationship between illness perception (IP) and post-traumatic stress disorder (PTSD), and the mediation role of cognitive emotion regulation (CER) among patients with burns.This study is multicenter and cross-sectional. Patients with a history of burn injury at three tertiary hospitals in mainland China were selected through purposeful sampling. Online surveys were used to gather data. Cognitive Emotional Regulation Questionnaire (CERQ), Brief Illness Perception Questionnaire (BIPQ), and Post‑traumatic Stress Disorder Checklist for DSM‑5 (PCL-5) were used to examine the link between IP, CER, and PTSD.216 patients completed the online questionnaires from July 2023 to July 2024 by purposive sampling. The mean score for the PCL-5 was 27.44 ± 13.49, for the BIPQ 49.39 ± 11.71, for the positive CER 44.87 ± 16.71, and for the negative CER 33.69 ± 8.59. Pearson correlation analysis showed IP was positively correlated with PTSD (r = 0.851, p＜0.05) and with negative CER (r = 0.626, p＜0.05). IP not only has direct effects on PTSD but also has indirect effects on PTSD by affecting positive and negative CER.Patients with burns in the early stage have a high level of PTSD, which was positively and significantly correlated with IP and negative CER, and negatively related with positive CER. CER plays a mediation role in the relationship between IP and PTSD. It is suggested that healthcare professionals need to pay attention to the patient's perception of the disease, and also need to stimulate the patient to take active behaviors to reduce the level of individual stress perception.Copyright © 2025 Elsevier Ltd and International Society of Burns Injuries. All rights reserved.