Diabetes mellitus is the most common cause of kidney disease worldwide, and of end-stage renal disease (ESRD) in the United States and elsewhere. Mortality rates of patients with diabetes mellitus (DM) on chronic dialysis exceed those of non-DM patients. ESRD and dialysis add to the complexity of glycemic management in this population. Abnormal glucoregulation includes reduced insulin sensitivity and renal clearance of the hormone. Implementation of dialysis affects glucose and insulin levels, while increasing insulin sensitivity. Tight glycemic control carries an increased risk of hypoglycemia in ESRD. Monitoring glycemic control with hemoglobin A(1c) (HbA(1c)) levels may be suboptimal because of analytical and clinical variability of the test. Recent studies on HbA(1c) and clinical outcomes in this population present complementary results on the role of glycemic control in patients with DM with ESRD.