ObjectiveTo analyze the risk factors for the prolonged time of intensive care unit (ICU) stay after isolated heart valve replacement. MethodWe retrospectively analyzed the clinical data of 400 patients underwent heart valve replacement surgery in our hospital in 2013 year. There were 208 males and 192 females with a mean age of 50.5±11.1 years ranging from 11-85 years. We divided them into an A group with the time of ICU stay shorter than 48 hours and a B group with the time of ICU stay longer than 48 hours. We recorded the demographic characteristics, preoperative data, intraoperative data and postoperative data and analyzed those data with univariate and multivariate methods. ResultThere was a statictical difference in the demographic characteristics, preoperative data, intraoperative data and postoperative data between the 2 groups (P < 0.05). The logistic result showed that if we didn't consider the postoperative factors the prolonged time of ICU stay statistically related with age over 70 year(OR 2.024, 95%CI 1.182-3.466, P < 0.05), the cardiac grade of New York Heart Association at Ⅲ-Ⅳ(OR 3.295, 95% CI 1.030-10.544, P < 0.05), preoperative hemoglobin concentration less than 120 g/l (OR 0.500, 95%CI 0.263-0.950, P < 0.05), and the cardiopulmonary bypass time more than 180 min (OR 2.486, 95%CI 1.006-6.143, P < 0.05). If we considered the postoperitive factors, the prolonged time of ICU stay statistically linked to the cardiopulmonary bypass time longer than 180 min (OR 3.295, 95% CI 1.030-10.544, P < 0.05), the postoperative blood glucose more than 10 mmol/l (OR 2.954, 95%CI 1.334-6.543, P < 0.05), and the pulling out trachea canula 24 hours after operation (OR 6.742, 95% CI 3.005-15.124, P < 0.05). ConclusionThe prolonged time of ICU stay after valve replacement surgery is associated with a number of risk factors before, during and after heart valve replacement surgery. Targeting the risk factors, especially the postoperitive risk factors, can be effective to shorten the ICU residence time.