Fasting levels of glycated haemoglobin, cholesterol and triglycerides were studied in 44 patients with non-insulin-dependent diabetes mellitus (NIDDM), 31 patients with insulin-dependent diabetes mellitus (IDDM) and 28 healthy Sudanese individuals. Results confirmed previous observations showing correlation of glycated haemoglobin with fasting blood glucose in NIDDM (r = 0.634; P less than 0.001), and with cholesterol in IDDM (r = 0.355; P less than 0.05). No correlation of glycated haemoglobin with triglycerides was observed in either group of diabetics. A negative correlation was demonstrated between glycated haemoglobin and the duration of diabetes (r = -0.552; P less than 0.01) in IDDM. It seemed that control improved in these patients as their diabetes progressed, probably through self-education.