Background <p>Trauma has emerged as a major cause of death worldwide. Inadvertent perioperative hypothermia (IPH) is closely related to the prognosis of trauma patients. However, risk factors related to intraoperative hypothermia have not been defined in this population.</p> Objective <p>This study aimed to analyze the risk factors and predictive value of these factors related to inadvertent intraoperative hypothermia in adults undergoing trauma surgery under general anesthesia.</p> Methods <p>Patients aged 18 years or older who underwent trauma surgery under general anesthesia at a tertiary hospital from January 2023 to May 2025 were retrospectively enrolled. The demographic, anesthesia-related and surgery-related data of the patients were collected. Inadvertent intraoperative hypothermia was identified as a core temperature monitored in nasopharynx &lt; 36℃. Univariate and multivariate analyses were used to identify factors associated with inadvertent intraoperative hypothermia. The area under the receiver operating characteristic (ROC) curve was used to verify the discriminative ability of multivariate logistic regression results.</p> Results <p>A total of 885 patients were analyzed, the incidence of inadvertent intraoperative hypothermia was 23.3% (95% CI 20.6%-26.2%). The risk factors associated with inadvertent intraoperative hypothermia included low body mass index (BMI) (OR = 0.932, 95%CI 0.887–0.979, <i>P</i> = 0.005), low base line body temperature (OR = 0.076, 95%CI 0.048–0.121, <i>P</i> &lt; 0.001), longer duration of surgery (OR = 1.221, 95%CI 1.011–1.476, <i>P =</i> 0.039), large volume of fluid infusion (OR = 1.033, 95%CI 1.000-1.067, <i>P =</i> 0.048) and combined positions (OR = 2.093, 95%CI 1.035–4.231, <i>P</i> = 0.040). ROC curve analysis showed that baseline body temperature (AUC: 0.793, 95%CI 0.757–0.829) had highest predictive efficiency for inadvertent intraoperative hypothermia among above-mentioned five factors. Meanwhile, the combination of all risk factors had the highest predictive efficacy (AUC: 0.835, 95%CI 0.804–0.866).</p> Conclusions <p>This study represents the first report on the incidence rate of inadvertent intraoperative hypothermia in patients undergoing trauma surgery and identify key risk factors including lower baseline body temperature, longer duration of surgery, lower BMI, more fluid infusion and combined positions. We also contribute the multifactor model demonstrated superior predictive value for inadvertent intraoperative hypothermia.</p> Clinical trial number <p>Not applicable.</p>