Insulin resistance (IR) is associated with an elevated PAI-1 level and by correlation with insulin and triacylglycerol (TG) levels. While in IR non-diabetics this relationship is close, in patients with NIDDM the mutual relationship is less marked and there are other factors which raise the PAI-1 levels such as proinsulin, oxidation stress or cytokines. Therefore achievement of satisfactory metabolic control, reduction of insulin and TG levels need not be associated with normalization of PAI-1. As it is an independent risk factor of atherosclerosis, further examinations are necessary in order to differentiate in more detail the possible causes of its rising level in order to obtain a rational basis for effective therapy.