['Early detection of renal dysfunction is important in burn patients. This study evaluated whether serum cystatin C (CysC) is a potentially accurate and sensitive marker for identification of reduced glomerular filtration rate (GFR) and the risk factors of impaired renal function in major burn patients.', 'A total of 48 adult patients with major burn injury were enrolled. Renal function was assessed using serum creatinine (sCr), 24-h urinary creatinine clearance (24-hCrCl), sCr-based formulae and CysC-based formulae on the second day and seventh day post-burn.', 'There was a high prevalence (27.1%) of acute impaired renal function in major burn patients in the first week post-burn. CysC-based formulae for estimated GFR (eGFR) are more accurate and sensitive for detection of impaired renal function than sCr-based formulae. Multivariate logistic regression analysis demonstrated that age (OR, 2.08; 95% CI 1.26-4.77) and the percentage of burn area (OR, 3.41; 95% CI 1.64-6.95) were independent risk factors of impaired renal function.'] Is serum cystatin C an early biomarker for assessment of renal function in burn patients?