The anatomic distortion created by scarring and adhesions from endometriosis offers a clear mechanism for reduced pregnancy rates. Ultrasonography and MRI are of variable accuracy in diagnosing deeply infiltrating endometriosis, with sensitivity ranging between 33 and 83%, based on location of lesions. Diagnostic laparoscopy or laparotomy is the only definitive way to diagnose pelvic endometriosis. This chapter focuses on specific treatments available to patients with endometriosis-associated infertility. Ovarian suppression was long held as the standard in treatment of endometriosis-associated infertility. Methods of suppression included progestins, danazol, and gonadotropin-releasing hormone agonists. Surgery may also address other mechanisms by which endometriosis causes infertility by eliminating the endometriosis lesions. The anatomical distortion typically associated with more severe endometriosis would preclude this alternative in patients with moderate to severe disease. Overall, with appropriate diagnosis and the use of various treatments, the overall prognosis for pregnancy in women with endometriosis is very favorable.