When evaluating the correlation between endometriosis and infertility with application of the evidence-based guidelines to establish causality in medicine, it becomes apparent that endometriosis causes infertility. This is supported by a strong and consistent association between the two in various settings (prevalence, natural conception, intrauterine insemination (IUI), and assisted reproductive technologies (ARTs)), evidence for a temporal relation, arguments for a dose-response gradient, and proven effects of the removal of lesions on infertility. Next to surgical treatment of endometriosis lesions, medically assisted reproduction treatments such as IUI and ART such as in vitro fertilization are cornerstones of the management of endometriosis-related infertility. Because the revised American Society for Reproductive Medicine (rASRM) staging system is poorly correlated with pregnancy rates as opposed to the Endometriosis Fertility Index (EFI), the latter should be used as the preferred clinical tool to counsel patients on their postoperative fertility management options.