Endometriosis affects at least one in ten women of childbearing age, yet it is often overlooked in emergency care. Clinicians should consider this diagnosis for any woman presenting with menstrual or ovulatory cyclic pain, dyspareunia, or chronic pelvic pain. In case of worsening pain in a patient with endometriosis, an underlying acute condition must be ruled out before considering an "endometriosis flare-up". Effective pain management remains the cornerstone of emergency care in endometriosis. It also plays a critical role in preventing premature surgical intervention, whose iatrogenic consequences may negatively impact patients' fertility.