Purpose: Serum cystatin C (sCyC) has long been known as a reliable biomarker of renal injury. However, it remains to be tested whether sCyC is a reliable biomarker to predict renal recovery after continuous renal replacement therapy (CRRT). Methods: A retrospective analysis of patients admitted to a tertiary 18-bed intensive care unit from January 2008 to December 2011 was performed. Univariate and multivariate regression analyses were performed to test the independent predictors of renal recovery. The diagnostic value of sCyC in predicting renal recovery was assessed using a receiver operating characteristic curve (ROC). Results: Older age and higher sCyC were independent risk factors of renal nonrecovery (OR: 1.40 and 4.76, respectively). The area under the ROC of sCyC to predict renal recovery was 0.87 (95% CI: 0.82-0.92), with a sensitivity and specificity of 80.5% and 83.5% at the cutoff of 2.98 mg/l. Conclusion: A high sCyC level at the initiation of CRRT is associated with poor renal outcome.