Endometriosis is a chronic disease, in which endometrial-like tissue is found outside the uterine cavity. Lesions are typically located in the true pelvis but can be found, in addition to extragenital endometriosis, in the respiratory system, the diaphragm, the pleura or the pericardium. As the extrauterine endometrial lesions undergo the menstrual cycle, they cause many symptoms, including pain, and besides infertility, they all mostly affect the quality of the patient’s life. Pharmacological management of endometriosis significantly increases in importance either as a first-line treatment or as a complementary therapy after surgery. Yet, current research on antagonists of the gonadotropin-releasing hormone (GnRH) has revealed their potential benefits in endometriosis treatment. Their mechanism of action is to down-regulate the hypothalamic–pituitary–gonadal axis and therefore induce a hypoestrogenic state. The resulting reduction of estrogen levels prevents disease progression and diminishes the recurrence rate after surgical removal of endometriosis. The present review summarizes recent reports of the role oral GnRH antagonists have as a significant treatment option for pain reduction in endometriosis patients.