Human serum albumin is composed of human mercaptoalbumin (HMA) with cysteine residues having reducing powers and oxidized human non-mercaptoalbumin. The aim of this study is to clarify whether such redox state of albumin (HSA-redox) influences the incidence of cardiovascular disease (CVD) in chronic kidney disease patients on regular hemodialysis (HD). We measured HSA-redox using high-performance liquid chromatography in 86 anuric HD patients. The association between HSA-redox and incidental CVD events was evaluated. Twenty patients experienced symptomatic CVD events (16 patients died) at the 2-year follow-up. The fraction of HMA (f(HMA)) showed a significantly lower value in patients with CVD than that without CVD, in both pre-HD (36.5 ± 5.8% and 44.6 ± 9.8%, respectively) and post-HD (57.2 ± 6.2% and 67.2 ± 7.4%, respectively). The adjusted odds ratio (OR) for the incidental CVD event in patients with pre-HD f(HMA) < 40% was 5.0 (95% CI; 1.2 to 21.3), and that in patients with post-HD f(HMA) < 60% was 20.6 (3.2 to 134.7). Likewise, the adjusted OR for the CVD death in patients with pre-HD f(HMA) < 40% was 2.5 (0.6 to 12.5), and that in patients with post-HD f(HMA) < 60% was 25.6 (2.5 to 262.8). In conclusion, HSA-redox is closely related to serious CVD incidence and mortality among HD patients.