There are conflicting reports of an association of ovarian antibodies, detected by immunofluorescence, with polycystic ovary syndrome (PCOS). The objective of this study was to evaluate the association of ovarian autoimmunity with PCOS. A validated immunoassay for ovarian antibodies was used to assess serum from women with PCOS and with menopause and normal cycling women as controls. The frequency of ovarian antibodies was similar (25%) among the controls and PCOS. Thus, unlike the association of ovarian antibodies detected with this test in patients with unexplained infertility and premature menopause, the prevalence of ovarian antibody in patients with PCOS is not significantly different to controls.