Approximately 7-12% of women in reproductive age are affected by PCOS[2] and 40 to 70 percent of them are overweight contributing to the clinical picture of PCOS and increased reproductive and metabolic disorder. In order to investigate the role of PAl-1 as a possible risk factor for the development of PCOS a group of 67 women with polycystic ovarian disease and 70 healthy controls were investigated for levels of PAI-1 and carriage of the promoter polymorphism 675 4G/5G in gene of PAl-1. The results of the DNA analysis showed a high carriage of polymorphism 675 4G/4G in promoter of PAI-1 gene in women with PCOS but not as significant (OR = 1.6645, p = 0.141). Serum levels of PAI-1 were significantly higher in total group of patients compared to controls. The levels of PAI-1 is correlated with carriage of 675 4G/5G polymorphism in the gene for PAI-1 (R = 0.534, p = 0.03) as well as wih BMI, like correlation coefficients were higher in the group with PCOS (0.572, p = 0.04). Data from the disease history showed a higher percentage of women with reproductive problems: 61.5% (early pregnancy loss and infertility) significantly higher in the group with PCOS (70.1% compared to 54.1%). The carriers of polymorphism 4G are at greater risk for early pregnancy loss than those with 5G (61.45% as compared to 36.8%), which confirms that carriage of the polymorphism 4G/5G 675 gene PAI-1 has a specific in multifactorial pathogenesis and expression of PCOS.