We hypothesized that serum cystatin C can be a more predictable marker of arterial stiffness than serum creatinine and creatinine-based glomerular filtration rate (GFR). The aim of this study is to evaluate whether serum cystatin C is related to arterial stiffness independently of serum creatinine in subjects for whom serum creatinine is normal. A total of 2,018 individuals (1,120 males, 898 females) were enrolled. Mean brachial-ankle pulse wave velocity (baPWV) was used as a marker of arterial stiffness and sex-specific analysis was performed. A positive relationship between baPWV and serum cystatin C (Y=1109.0548+329.9102X, r(2)=0.056, p<0.001) was found in males. Stepwise multivariate regression analysis in males showed that age, waist circumference, heart rate, cystatin C level, triglyceride level, and fasting glucose were independent contributors to baPWV. In females, a positive relationship between baPWV and serum cystatin C (Y=1035.7828+402.2970X, r(2)=0.090, p<0.001) was found. Stepwise multivariate regression analysis showed that age, heart rate, cystatin C level, fasting glucose and insulin level were independent contributors to baPWV. Age, heart rate, fasting glucose and serum cystatin C were the significant variables in both genders that contributed to baPWV. In conclusion, this study confirmed that serum cystatin C was related to pulse wave velocity even in subjects with normal serum creatinine. This finding suggested that cystatin C could be a more predictable marker of arterial stiffness than serum creatinine and creatinine-based GFR.