The ENZIAN-Score is presented as a new instrument to classify the deep infiltrating endometriosis. Especially the retroperitoneal part of the severe endometriosis is focussed on. In analogy to an oncological staging four different stages are pronounced. The localisation and the expansion of the endometriosis nodule was indicated to different subgroups. The still used rAFS-score is of no clinical evidence, as we pointed out in a retrospective study of our patients with severe intestinal endometriosis.