PAI-1 has become recognized as a central molecule linking pathogenesis and progression of thrombotic vascular events, including stroke. Clinical and experimental studies show that PAI-1 deficiencies cause accelerated fibrinolysis and bleeding, whereas elevated PAI-1 plasma levels are associated with vascular thrombosis. Raised PAI1 plasma levels are related to a 1-bp guanine deletion/insertion (4G/5G) polymorphism in the promoter of the PAI1 gene. The 4G allele is associated with higher plasma PAI1 transcription and activity. In the current study, the association of higher PAI-1 plasma levels and the prevalence of the 4G/5G polymorphism in the PAI-1 gene promoter region in young patients with stroke were explored. Significantly, higher PAI-1 levels were observed in patients when compared to controls (p =002). The 4G/5G polymorphisms were significantly associated with increased PAI-1 levels, with the variant homozygous 4G/4G corresponding to mean values in patients versus controls.