The present investigation is devoted to the development of the pain syndrome in endometriosis patients. 150 women with a genital endometriosis of the reproductive age were investigated. On the base of the correlative analysis a high level of dependence between the pain syndrome severances, level of peroxidation (malonic dialdehyde) and level immune depression was revealed. Inflammation reaction (DTH) takes a significant role in the pain syndrome in endometriosis. Severance of the endometriosis development is not defined by the spreading stage, it is defined by the pain syndrome severance, which correlates with the anxiety level and depression and has extra-organic features.