BACKGROUND Postoperative delirium dramatically increases the mortality and morbidity of patients undergoing cardiac surgery. Preoperative education has been proven to be effective in improving recovery and reducing complications. However, there is rare evidence of individualized education for the delirium. This study aimed to investigate the effect of preoperative personalized education on postoperative delirium of patients undergoing cardiac surgery. METHODS A total of 133 adult patients receiving cardiac surgery in a single center were enrolled in this study and randomized into the experimental group (n=67) and the control group (n=66), who were given the preoperative individualized education intervention and routine care respectively. The primary endpoint of delirium and other clinical outcomes were observed and compared. RESULTS All patients completed this trial without a significant difference between the two groups in baseline characteristics. The incidence of the delirium of the experimental group was significantly lower than that of the control group (10.4% vs. 24.2%, P=0.038). There was no statistical difference between two groups in hospital-stay and other complications, while the mechanical ventilation time and ICU stay of the experimental group was significantly lower (MV time: 13.7±7.6 vs. 18.6±9.8 h, P=0.002; ICU stay: 31.3±9.1 vs. 36.5±10.4 h, P=0.003). CONCLUSIONS Preoperative individualized education intervention can reduce the incidence of postoperative delirium and promote the recovery of patients receiving cardiac surgery.