Aortic stiffness and proteinuria are cardiovascular risk factors that are generally associated with each other. We analysed whether this is true for patients with chronic kidney disease (CKD). We hypothesized that in CKD patients of young age and predominant sole renal disease, aortic stiffness has no predictive value for proteinuria. In a cross-sectional setting, 144 patients with severe-to-mild CKD (estimated glomerular filtration rate (eGFR) 0 to <90 ml min(-1) 1.73 m(-2)) were analysed for stiffness, as measured using carotid-femoral pulse wave velocity (C-F PWV), and proteinuria, as determined using protein-creatinine ratio from morning spot urine. In stepwise linear regression analysis, C-F PWV predicted protein-creatinine ratio and vice versa. Younger patients (<50 years) with proteinuria had predominant glomerulonephritis. These were characterized by lower C-F PWV despite similar renal function when compared with younger patients without glomerulonephritis. We conclude that in CKD patients a general relationship exists between aortic stiffness and proteinuria. It is noted that this relation is lost in young CKD patients with predominant sole renal disease. In this study, C-F PWV is not predictive for proteinuria as renal disease is the leading cause of proteinuria.