Homocysteine is a risk factor for ischemic heart disease; similarly as is hyperlipidemia or insulin resistance, which frequently occur in women with polycystic ovary syndrome. We examined the relationships between thiols and hormonal status or insulin resistance in 40 women (aged 25.8 +/- 7 years) with polycystic ovary syndrome and in 11 controls (33 +/- 5 years). Blood levels of homocysteine, glutathione, total and high density lipoprotein (HDL)-cholesterol, triglycerides, insulin, sex hormone-binding globulin, testosterone, androstenedione, dehydroepiandrosterone sulfate, and estradiol were determined. Student's t test and Spearman correlations were computed after adjustment for body mass index (BMI) and age. Homocysteine was significantly higher in polycystic ovary syndrome patients than in the control group (10.3 +/- 2.87 vs. 8.78 +/- 2.75 micromol/l; p < 0.05). In women with polycystic ovary syndrome, there were significant positive correlations between homocysteine and androstenedione (r = 0.329; p < 0.05) and glutathione and dehydroepiandrosterone sulfate (DHEA-S) (r = 0.469; p < 0.05). We conclude that homocysteine is increased in women with polycystic ovary syndrome and is probably linked to androgen levels but not to markers of insulin resistance or with lipid metabolism.