This study investigates the reliability of glycated haemoglobin, measured by electroendosmosis or by affinity chromatography, fructosamine, and albumin adjusted fructosamine, as indices of glycaemic control in Type 1 diabetes complicated by chronic renal failure. Twenty uraemic diabetic patients took part in the study, including 5 patients managed conservatively, 6 on CAPD, 3 on haemodialysis, and 6 renal transplant recipients. Results were compared with those from 15 diabetic subjects with normal renal function. In renal patients, there was significant correlation between glycated haemoglobin measured by electroendosmosis (r = 0.45; p = 0.04) or by affinity chromatography (r = 0.57; p = 0.01) and mean capillary blood glucose concentrations over the previous 6 weeks. The regression equations did not differ significantly between subjects with renal failure and those with normal renal function, suggesting that similar ranges can be used in interpreting glycated haemoglobin results from each group of patients. Patients on haemodialysis may be an exception; there was evidence that glycated haemoglobin may be misleadingly low in such subjects. Fructosamine correlated significantly with mean blood glucose concentrations measured over the previous week in patients with normal renal function (r = 0.75; p = 0.001), but not in patients with chronic renal failure (r = -0.1; p = 0.71). Calculation of an albumin adjusted fructosamine result failed to improve the correlation with blood glucose concentrations. The use of fructosamine cannot be recommended as an index of glycaemic control in uraemic patients.