Objective To investigate the long-term prognosis and possible risk factors of acute kidney injury(AKI)following cardiac surgeries. Methods Clinical data of 941 patients undergoing open heart surgery from January 2004 to June 2007 were retrospectively analyzed.Survival and renal function of above patients were informed through telephone or clinic follow-up till February 2010.Long-term survival was analyzed using risk-adjusted Cox proportional hazards regression model. Results Of the 941 patients after cardiac surgery,275(29.2%)developed AKI and 666(70.8%)did not.Survival was worse in patients with AKI(67.8%vs 85.6%,P<0.01)and was proportional to its severity (AKIN 1,2 and 3 stages:70.7%,62.3%and 58.6%,P<0.01).Although 90.5% of patients had complete renal recovery after AKI at discharge of hospital,they still had an increased risk for death during follow-up compared with patients without AKI (69.6% vs 85.6%,P<0.01).In the Cox proportional hazards regression model,age(HR=2.238),anemia (HR=1.625),prolonged operation time (HR=1.153),AKI severity (HR=1.473)were independent risk factors for long-term prognosis after cardiac surgery.At the end of the follow-up,patients with AKI had statistically higher Scr than non-AKI patients(107.6 μmol/L vs 83.0 μmol/L,P=0.014),and among those AKI patients,34.0%progressed into CKD 3-5 stages,34.8%developed double serum creatinine. Conclusions AKI is a risk factor for the long-term prognosis of cardiac surgery.Patients with complete renal recovery after AKI still has an increased risk for death and poor renal function compared with patients without AKI.