PAI-2 is one of the regulators of the fibrinolytic system. The importance of the fibrinolytic cascades in the pathogenesis of myocardial infarction has been demonstrated by many investigators. Recently, some investigators have shown that two variants of PAI-2, designated A and B, are associated with the formation of large molecular PAI-2 complexes. This polymorphism is therefore present a genetic predisposition for the development of coronary artery disease and multiple sclerosis. Therefore, the prevalence of this polymorphism among 45 patients with MI and 20 control subjects was investigated. The AA genotype of the PAI-2 gene was found to be more frequent among those subjects with MI. These data provide evidence that a polymorphism of the PAI-2 gene is associated with an increased risk of MI.