A number of investigations have previously been carried out to examine inter-relationships between hypercuricaemia, gout, and levels of plasma lipids, usually with particular reference to glycerides and cholesterol. The present study was designed to compare the levels not only of glycerides and cholesterol, but also of phospholipids and free fatty acids, in gout patients with those in a group of very closely matched control subjects; and to determine, in the gout patients, whether there was any relationship between levels of these lipid fractions and the endogenous production of uric acid as measured by urinary levels of uric acid on a low-purine diet.Plan of study 27 British patients with primary gout (25 men and 2 women) participated in the study. Some of them were on urate-lowering treatment (allopurinol or uricosuric agents) at the time when blood was taken for lipid estimations, but plasma and urinary levels of uric acid had been estimated on a low-purine diet before treatment was started.A control group of 27 subjects was taken from hospital patients suffering from a wide variety of medical and surgical conditions. None had gout or hyperuricaemia; all were of reasonable social orientation, all were taking normal diets and none was grossly obese. Initial investigations in all subjects, gout and control, excluded predisposing causes for hyperlipidaemia. The control group was matched with gout patients for age, sex, blood pressure, alcohol intake, and the presence of ischaemic vascular disease. The two groups were also matched for ponderal index 13igh (in.) which tends to be lower \VYweight (lb.)