Since red blood cell survival time is shortened in patients with diabetes mellitus (DM) on hemodialysis (HD), it is unlikely that indices of glycemic control accurately reflect the glycemic state of these individuals. In this study, in order to determine the best index of glycemic control in diabetic patients on HD, we measured HbAlc, 1,5-anhydroglucitol (1,5-AG), fructosamine (Fr) and glycated albumin (GA) in 31 diabetic patients on HD (20 males and 11 females, mean age: 66.9 years), and examined the correlation between each index and predialysis plasma glucose level. Since the mean values of predialysis plasma glucose during the final 2 and 4 weeks before the study were best correlated with HbAlc, this parameter was considered to be the most reliable index of glycemic control in diabetic patients on HD. GA was more closely correlated with mean values of predialysis plasma glucose during the final 2 and 4 weeks, than any other index of glycemic control, followed by HbAlc. In conclusion, HbAlc is considered to be the most reliable index of glycemic control in diabetic patients on HD.