Objectives We aimed to develop and validate a postoperative delirium (POD) prediction model for patients admitted to the intensive care unit (ICU). Design A prospective study was conducted. Setting The study was conducted in the surgical, cardiovascular surgical, and trauma surgical ICUs of an affiliated hospital of a medical university in Heilongjiang Province, China. Participants This study included 400 patients (≥18 years old) admitted to the ICU after surgery. Primary and secondary outcome measures The primary outcome measure was postoperative delirium assessment during ICU stay. Results The model was developed using 300 consecutive ICU patients and was validated using 100 patients from the same ICUs. The model was based on five risk factors: Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity; acid-base disturbance; and history of coma, diabetes, or hypertension. The model had an area under the receiver operating characteristics curve of 0.852 (95% confidence interval: 0.802–0.902), Youden index of 0.5789, sensitivity of 70.73%, and specificity of 87.16%. The Hosmer-Lemeshow goodness of fit was 5.203 (P = 0.736). At a cut-off of 24.5%, the sensitivity and specificity were 71% and 69%, respectively. Conclusions The model, which used readily available data, exhibited high predictive value regarding risk of intensive care unit postoperative delirium (ICU-POD) at admission. Use of this model may facilitate better implementation of preventive treatments and nursing measures.