The exposure to adverse childhood experiences has been associated with the subsequent development of several chronic health conditions, including pelvic pain. Endometriosis is a chronic disease characterized by the growth of endometrial-like tissue outside of the uterus, and is considered a common cause of chronic pelvic pain and infertility in reproductive-age women. However, the topic of pelvic pain and endometriosis is fraught with many challenges. This applies not just to clinical practice but also to research where many inconsistencies relating to pelvic pain and endometriosis definitions are encountered. A review was carried out for articles exploring the association of adverse childhood experiences and endometriosis. Studies addressing self-reported endometriosis suggested a relationship with childhood adversity, whilst papers relying on surgically diagnosed lesions of endometriosis irrespective of clinical presentation did not. This highlights the potential bias associated with the inconsistent use of the expression “endometriosis” in research.