This study examined the relationship between the personal predisposing factors of patients and the severity of pressure injuries (PIs) developed during surgery. This retrospective cohort study collected 439 cases of peri‐operative PIs. Using binary logistic regression to identify the variables associated with PI severity, the effects of interactions between associated variables were then tested. The results of this study revealed that among the personal predisposing factors, only higher patient age (P = .001) and higher body mass index (P < .001) posed a greater risk of stage 2 PIs or higher. Among the surgery‐related facilitating factors, only patients who were placed in the prone position during surgery and patients who lost ≥1000 mL of blood during surgery were at greater risk of stage 2 PIs or higher, compared, respectively, to those placed in the supine position and those who lost ≤100 mL of blood. Furthermore, the amount of blood lost during surgery moderated the influence of age on PI severity. For elderly patients who are expected to lose a large blood volume during surgery or lose an immeasurable amount of blood due to the use of cardiopulmonary bypass, taking more precautionary measures to prevent PIs is recommended.