Lipids and lipoproteins were analysed in forty-one survivors of stroke, aged less than 65 years, and the same number of age and sex matched controls without vascular disease. The stroke subjects had no evidence of coronary artery or peripheral vascular disease. High density lipoprotein cholesterol was significantly lower (1.19 +/- 0.06 mmol/l) in the stroke subjects than the controls (1.47 +/- 0.07 mmol/l). Triglyceride was also elevated in the stroke subjects, but this was confined to those who were taking antihypertensive treatment which included beta-blockers and/or thiazides. The low levels of high density lipoprotein in stroke were independent of hypertension or its treatment. Thus low levels of high density lipoprotein appear to be associated with cerebrovascular disease, while elevated triglyceride is a complication of anti-hypertensive therapy.