Endometriosis (EM) is defined by the presence of tissue histologically and functionally similar to the endometrium outside the uterus. EM has been mostly reported in the pelvis. Intraspinal endometriosis (IEM) is so rare that only four cases have been reported in the literature, to our knowledge.1-4 Two years ago, a patient was admitted to the Second Affiliated Hospital of Lanzhou Medical College and was treated successfully (with 2 years of follow-up).