BACKGROUND: Ovarian antibodies as detected by indirect immunofluorescence have been used to detect ovarian autoimmunity, but to our knowledge the rate of false positive findings using this method has never been reported. METHODS: Here we examine whether a commercially available ovarian antibody test system, using cynomologous monkey ovary, might be useful in the diagnosis of autoimmune premature ovarian failure. The test was performed in a blinded manner in 26 young women with 46,XX spontaneous premature ovarian failure, in 26 control women with regular menstrual cycles (matched for age, race, and parity) and 26 control men (matched for age and race). We also compared the frequency of other autoantibodies associated with ovarian autoimmunity. RESULTS: As a group young women with premature ovarian failure had an increased incidence of thyroid and gastric parietal cell autoimmunity (p < 0.05). Unexpectedly, however, nearly one third (31%) of normal control women had ovarian antibodies using the commercially available test. One half of young women with premature ovarian failure were found to have ovarian antibodies (P = 0.26). In our own laboratory we found similar results and we were unable to improve the specificity of the test. None of 26 men were found to have ovarian antibodies (P < 0.001). CONCLUSION: Since approximately one third of normal women were found to have ovarian antibodies using the system under study, we conclude that ovarian antibodies as detected by this indirect immunofluorescence method have poor specificity. The specificity of any ovarian antibody test should be established before it is used clinically.