Abstract: Endometriosis is a common gynaecological disorder, and although extensively studied its etiopathogenic mechanisms remain unclear. Stem cells are undifferentiated cells that have the ability to self-renew as well as to produce more differentiated daughter cells in particular conditions. Recently, the identification of putative endometrial stem/progenitor cells (SPCs) has emerged as a possible origin of endometriotic lesions and a new mechanism for endometriosis etiology. This new hypothesis could account for the etilogy of all kinds of endometriosis, it has been raising considerable scientific and clinical interest not only for the breakthrough of the pathogenesis, but also for the new target on therapy.