Objective To investigate the effects of tight blood glucose control on the shortterm prognosis of the patients after heart valve replacement, in order to improve treatment effectiveness and lower postoperative complications. Methods A total of 240 patients including 150 males and 90 females underwent mitral valve replacement or mitral and aortic valve replacement were enrolled in this study from January 2007 to December 2008 at the cardiac surgery department of Renmin hospital of Wuhan university. The age of these patients ranged from 19 to 65 years old with an average age of 53.33 years. According to insulin administration time and blood glucose control level, they were randomly separated into two groups. In the experimental group, there were 121 patients who received continuous insulin infusion to maintain postoperative glucose level between 4.4 and 6.1 mmol/L, while 119 patients in the control group received insulin infusion when their glucose level went higher than 11.1 mmol/L to control the level between 6.1 and 11.1 mmol/L. Then the postoperative wound infection, malignant arrhythmia rate, the assisted ventilation time, intensive care unit(ICU) stay time and count of neutrophils were compared and analyzed. Results There was no hospitalized death in both groups. The rate of wound infection（3.31% vs.10.08%, χ2=4.430,P=0.035）, the assisted ventilation time（9.02±2.73 h vs. 10.01±3.58 h, t=2.280,P=0.024）, time for count of leukocytes to decrease to the normal level（11.04±3.16 d vs. 12.05±3.76 d, t=2.168,P=0.031）, average hospitalization time（13.49±3.81 d vs. 14.51±4.02 d,t=2.017,P=0.045）, and count of neutrophils on the third day（0.82±0.04 vs. 0.84±0.05, t=2.644,P=0.009） in the experimental group were significantly lower or shorter than those in the control group. But there was no significant difference between both groups in ICU stay time and the rate of malignant arrhythmia. Conclusion Tight blood glucose control can lower the rate of postoperative wound infection, shorten the assisted ventilation time and hospitalization time, and reduce the usage of antibiotics in patients after heart valve replacement. Accordingly, it can enhance the curative effect, reduce overall medical expenses, and improve prognosis.