Pressure ulcers are a common complication of immobility and frequently occur in surgical patients. The occurrence of pressure ulcers is affected by many factors, such as operation time and position, anesthesia method, and postoperative nursing. The aim of this study was to investigate the Munro Pressure Ulcer Risk Assessment Scale’s value in predicting acute pressure ulcers in general anesthesia patients. This case-control study included patients who underwent more than 2 hours of general anesthesia in our hospital from January 2018 to December 2020. The case group comprised 42 patients who had pressure sores in surgical compression sites within 3 days after surgery. The control group consisted of 84 patients without acute pressure sores after surgery. Baseline patient data were compared between the two groups, and a logistic multivariate model was used to analyze potential risk factors for acute pressure ulcers. The Munro Pressure Ulcer Risk Assessment Scale scores and Braden scale scores were compared between the two groups during and after surgery. A receiver operating characteristic curve was used to evaluate the clinical value of the two scales (administered at the two time points) in predicting the occurrence of acute pressure ulcers after surgery. The operation and anesthesia times of patients in the case group were longer than those in the control group ( P < 0.05 ). The proportion of comatose patients and patients with diabetes were significantly higher in the case group. While the case group had higher Munro scores during and after surgery compared to the control group ( P < 0.05 ), Braden scores at the corresponding time points were lower ( P < 0.05 ). The following variables were identified as independent risk factors of acute pressure ulcers: prolonged operation time and anesthesia time, increase in Munro scores during and after operation, decrease in Braden scores during and after operation, and comatose status ( P < 0.05 ). The area under the receiver operating characteristic curve (AUC) of the postoperative Munro score for predicting postoperative pressure ulcer risk was 0.774; the sensitivity and specificity were 67.73% and 80.58%, respectively. The AUC of the intraoperative Braden score for predicting postoperative pressure ulcer risk was 0.836, with a sensitivity of 78.95% and specificity of 78.00%. The AUC of the postoperative Braden score for predicting postoperative pressure ulcer risk was 0.809, with a sensitivity of 73.58% and specificity of 64.26% ( P < 0.05 ). Our results indicate that the intraoperative Munro Pressure Ulcer Risk Assessment Scale is highly effective for predicting the risk of postoperative pressure ulcers in surgical patients who require general anesthesia.