Soluble intercellular adhesion molecule-1 (sICAM-1) is ranked as one of the endothelial dysfunction markers and factors predicting diseases of the cardiovascular system. The main objective of this study was to assess the serum concentration of sICAM-1 in women with polycystic ovary syndrome (PCOS) and to verify correlations between serum sICAM-1 levels and selected anthropometric, metabolic and hormonal indices. The study assessed 57 women with PCOS (mean age 28.2 +/- 6.4 years). That group was further divided into two subgroups: the first with body mass index (BMI) < or =25 kg/m2 (21 women of mean age 27.4 +/- 7.0 years) and the second with BMI >25 kg/m2 (36 women of mean age 28.6 +/- 6.0 years). In the control group there were 22 healthy women (mean age of 31.6 +/- 8.5 years). That group again was divided accordingly to BMI into two subgroups: the first with BMI <25 kg/m2 (ten women, mean age 30.2 +/- 8.4 years) and the second with BMI > 25 kg/m2 (12 women, mean age 31.7 +/- 8.7 years). The results demonstrated statistically significantly higher mean concentrations of sICAM-1 in women with PCOS as compared to healthy individuals from the whole control group and also from the control subgroup of women with BMI >25 kg/m2. There was no statistically significant difference in sICAM-1 concentration between the PCOS group and the control subgroup with BMI < or =25 kg/m2 In conclusion, higher concentrations of sICAM-1 in women with PCOS may confirm the presence of a higher risk for cardiovascular diseases in this group. Further studies are therefore necessary to identify both the factors that are responsible for the increase in sICAM-1 concentration and the clinical usefulness of routine sICAM-1 measurement in females with PCOS.