The relationship between hypertension, glucose metabolism, fibrinogen and plasminogen activator inhibitor of endothelial cell type (PAI-1) was studied under conditions in which the influence of obesity and adipose tissue distribution (waist/hip ratio) were controlled. Twenty-two non-obese, middle-aged men with normal blood pressure (n = 11) and untreated mild hypertension (n = 11), respectively, participated in the study. Cholesterol, triglyceride and insulin levels were higher in hypertensive men than in the control group. Glucose disposal was studied as an indicator of insulin sensitivity using the euglycaemic clamp technique. The insulin effect tended to be less marked in men with hypertension. PAI-1 was higher in hypertensive men compared to the controls. A strong positive correlation was observed between PAI-1 and insulin levels as well as blood pressure. PAI-1 and fibrinogen levels correlated negatively with the rate of glucose disposal. Thus, even in these non-obese and mildly hypertensive individuals, an enhanced metabolic risk factor profile for cardiovascular disease was found. The metabolic aberrations were related to elevated fibrinogen and PAI-1 levels which, in turn, increase the risk of thrombus formation.