We aimed to evaluate plasma plasminogen activator inhibitor-1 (PAI-1) antigen levels in women with polycystic ovary syndrome (PCOS) and different levels of adiposity and PCOS phenotypes. We studied 199 women with PCOS and 50 age-matched healthy women divided in normal weight (n=100 and n=25, respectively) and overweight/obese (n=99 and n=25, respectively). Normal weight and overweight/obese patients with PCOS were further divided in patients diagnosed according to the 1990 criteria (i.e. with anovulation and hyperandrogenemia; 1990 criteria group) and in patients with the additional phenotypes introduced in 2003 (i.e. with polycystic ovaries and either anovulation or hyperandrogenemia; additional 2003 criteria group). In normal weight subjects, plasma PAI-1 levels did not differ between women with PCOS (regardless of group) and controls, or between the 1990 criteria and the additional 2003 criteria groups of PCOS. In overweight/obese subjects, plasma PAI-1 levels were higher in both the 1990 criteria and the additional 2003 criteria groups of PCOS compared with controls (p<0.001 and p=0.004, respectively), but did not differ between the 1990 criteria and the additional 2003 criteria groups of PCOS. In conclusion, plasma PAI-1 levels are elevated in overweight/obese women with PCOS but not in normal weight women with this syndrome. Plasma PAI-1 levels do not differ between the phenotypes of PCOS.