Vascular calcifications are an important risk factor for cardiovascular mortality and morbidity in patients with chronic renal failure. Osteoprotegerin, a soluble decoy receptor for receptor activator NFkB ligand, has emerged as an independent predictive factor of atherosclerosis and vascular calcification in hemodialysis patients. Sparse data are available on the evolution of osteoprotegerin after renal transplantation. The aim of this study was to follow the evolution of serum osteoprotegerin levels and biochemical risk factors after renal transplantation. Forty patients were included. Blood samples for analysis were collected before and 3 months after renal transplantation. Besides the expected diminution in calcium-phosphate product, we have shown an early normalization of osteoprotegerin (10.05 +/- 4.77 pmol/L to 4.59 +/- 2.26 pmol/L). This study demonstrates that kidney transplantation improves this risk factor for vascular calcifications. However, these preliminary results should be confirmed and extended by the follow-up of vascular calcifications in the long term.