The role that autoantibodies play in infertility remains uncertain. There are conflicting data regarding the prevalence of autoantibodies in women with endometriosis. Certainly no one has demonstrated an association between the presence of antibodies in women with endometriosis and infertility. Despite intensive study, there is also no consensus on a role of autoantibodies to the zona pellucida as a cause of infertility. Recently, much attention has been focused on autoantibodies and infertility particularly with regards to phospholipid antibodies and their effect on IVF success rates. The literature suggests that women with infertility have an increased prevalence of phospholipid antibodies compared to fertile women. However, the presence of these antibodies has not been associated with a worsened prognosis for IVF cycles. Many questions remain to be answered. What is the cause of this apparently increased prevalence of autoantibodies in infertile women? Do these autoantibodies cause infertility or are they merely associated with some other condition which is actually causitive? Finally, can treatment of autoantibodies improve pregnancy rates in infertile couples after IVF or other infertility treatments? The answers to these questions should be sought by carefully conducted trials with appropriate control groups. Subjecting patients to expensive testing and 'treatments' before these answers are known is not consistent with good scientific or medical practice.