Endometriosis is characterised by ectopic endometrial tissue, which can cause dysmenorrhoea, dyspareunia, non-cyclical pelvic pain, and sub fertility. Final diagnosis is made by laparoscopy, but can also be helped by imaging. Most endometrial deposits are found in the pelvis (ovaries, peritoneum, uterosacral ligaments, pouch of Douglas, and rectovaginal septum). Extra pelvic deposits, including those in the umbilicus and diaphragm, are rare. Endometriomas are cysts of endometriosis within the ovary. Endometrial implants are responsible of pelvic adhesions or visceral infiltration. Consequences of these disease are often severe, from pelvic chronic pain until ureteral or rectal invasion. Diagnosis is difficult. Ultrasonography is able to detect ovarian endometriomas or adenomyosis but can not detect deep posterior endometriosis. MRI. is actually the more accurate examination for diagnosis and presurgical staging for endometriosis. Nevertheless, the knowledge of MRI technical parameters, and rules of interpretation are necessary for diagnosis accuracy, due to difficulty to detect the lesions. In this review, we will successively describe endometriosis physiopathology and imaging with different locations, with a particular attention to MRI, in order to allow adequate diagnosis and staging.