Plasma lipid profiles--total cholesterol (TC), LDL-cholesterol, HDL-cholesterol, triglycerides and phospholipids--were studied in relation to two parameters of diabetic control (fasting blood sugar (FBS) for short-term control and glycosylated haemoglobin (HBA1C) for long-term control) in 46 diabetic patients (22 insulin-dependent (IDDM) and 24 non-insulin dependent (NIDDM] and 22 non-diabetic control subjects. We confirmed the positive correlation between FBS and HBA1C. All diabetic patients had significantly higher triglyceride levels (P less than 0.05) than controls, which were not influenced by degree of glycaemic control. NIDDM patients tended to have higher than normal TC levels (P less than 0.05). In IDDM, TC level was positively correlated with HBA1C (r = 0.37, P less than 0.05), and negative correlations were established between FBS and HDL-cholesterol (r = -0.46, P less than 0.02) and the HDL-cholesterol:TC ratio (r = -0.49, P less than 0.01), suggesting an increased atherogenic risk with poorer diabetic control. It is concluded that lipoprotein abnormalities exist in Nigerian diabetics, though not as consistently as in Caucasians. The differences may be due to, among other factors, differences in genetic make-up, diet (typical African diet being rich in plant fibre and poor in cholesterogenic nutrients) and aetiology of the diabetic state (tropical diabetes being highly heterogeneous and now thought to be linked to malnutrition).