The common carotid intima-media thickness (CC IMT) is a strong predictor for cardiovascular disease in patients with end-stage renal failure. However, little is known about possible associations between potential cardiovascular risk factors such as serum total homocysteine concentrations (tHcy) and the CC IMT. Thus, we investigated (a) the course of tHcy levels after renal transplantation (RTX) and (b) the relationship between CC IMT and tHcy in 53 renal allograft recipients with chronic renal failure before transplantation and 3, 6, and 12 months after transplantation. Exclusion criteria were volume overload, symptomatic coronary artery disease, symptomatic cerebrovascular disease, peripheral artery disease, heart failure, valvular heart disease, diabetes mellitus, severe hypercholesterolemia, and blood pressure above 159/89 mmHg at the time of the investigation. In all renal allograft recipients, a carotid high-resolution B-mode ultrasound measurement of the CC IMT was performed. Eighteen patients had normal ( < 20 micromol/L) pre-transplant (U0) tHcy, 25 had moderately elevated (20-40 micromol/L) pre-transplant (U0) tHcy, and 10 had severely elevated (> 40 micromol/L) pre-transplant (U0) tHcy. After 12 months of follow-up time (U12), no statistically significant differences concerning the tHcy levels could be detected between the groups (average serum tHcy 16.4 micromol/L +/- 1.1 micromol/L). The CC IMT did not differ significantly between the three tHcy groups at any time within the present follow-up. This was also true for the 'wall-to-lumen ratio'. A multiple forward stepwise regression analysis showed that the reduction of the CC IMT was positively correlated with gender (p < 0.01), glucose levels at U12 (p < 0.05; r2 = 0.96), systolic arterial blood pressure at U12 (p < 0.05; r2 = 0.97), and with the intact parathyroid hormone levels at U0 (p < 0.01; r2 = 0.98). In conclusion, (a) tHcy decreases significantly after RTX, but (b) does not influence the CC IMT thickness independently.