Females with polycystic ovary syndrome (PCOS) are characterized by several metabolic abnormalities that favor the development of atherosclerosis. Atherosclerosis is possibly a chronic inflammatory process, and the markers of the inflammatory state, such as C-reactive protein (CRP) and fibrinogen may be useful to assess the global risk of developing cardiovascular diseases. These proteins might be helpful in finding females with subclinical atherosclerosis. The purpose of this study was to assess the serum CRP and fibrinogen concentrations in young females with PCOS and to clarify the possible correlations between their levels and selected anthropometric, metabolic and hormonal indices. Study assessed a group of 57 females with PCOS (mean age 28.2+/-6.4 years). That group was further divided into two subgroups: the first with body mass index (BMI)</=25 (21 females of mean age 27.4+/-7.0 years) and second with BMI>25 (36 females of mean age 28.6+/-6.0 years). In the control group there were 22 healthy females (mean age 31.6+/-8.5 years). That group was again divided into two subgroups: the first with BMI</=25 (10 females, mean age 30.2+/-8.4 years) and second with BMI>25 (12 females, mean age 31.7+/-8.7 years). Results demonstrated statistically significantly higher CRP concentration in females with PCOS compared to healthy individuals in both BMI subgroups. PCOS females showed also higher plasma insulin levels. There was, however, no statistically significant difference in fibrinogen concentrations. The hormonal profile of females with PCOS seems to influence the concentration of CRP and fibrinogen in different ways. This was evident in the positive correlation between plasma fibrinogen and androstenedione and in the lack of correlation between CRP and androgens and in the positive correlation between CRP and estradiol and the negative correlation between fibrinogen and estradiol. In conclusion, high CRP concentration in females with PCOS probably speaks for a higher risk for cardiovascular diseases.