We investigated the impact of glycemic control on the emergence of cardiovascular disease (CVD) in diabetic patients who were on maintenance hemodialysis in a prospective observational study. One hundred and thirty-four diabetic hemodialysis patients (63 +/- 10 years-old, hemodialysis duration of 4.5 +/- 3.9 years) at a single dialysis center were enrolled. The cohort was observed prospectively for 5 years, and the emergence of fatal and non-fatal CVD was recorded. Patients were categorized into two groups; good (mean hemoglobin (Hb) A1C <7.0%, N = 65) and poor HbA1C (mean HbA1C > or = 7.0%, N = 69). The relationship between glycemic control and CVD emergence was evaluated by Kaplan-Meier estimation and Cox proportional hazard models. During the follow-up period, 50 CVD events were observed. The cumulative CVD incidence in the poor HbA1C group was significantly higher than that of the good HbA1C group, as determined by Kaplan-Meier estimation (P = 0.0250, log-rank test). After adjustment for gender, age, duration of dialysis, and past history of CVD, a multivariate Cox proportional hazard model showed that poor HbA1C was a significant predictor of CVD events (hazards ratio [HR] 1.828 [95% CI, 1.008-3.314], P = 0.0470). When ischemic heart disease, cerebral infarction, and arteriosclerosis obliterans were determined as an endpoint, both HbA1C levels and the poor HbA1C group were significant predictors for the emergence of CVD (HR 1.269 per 1% HbA1C [95%CI, 1.022-1.574], P = 0.0307,and HR 2.816 [95% CI, 1.377-5.759], P = 0.0046, respectively). In diabetic hemodialysis patients, poor glycemic control is a significant, independent predictor of the emergence of CVD, indicating the importance of careful management of glycemic control in hemodialysis patients.