[en] Stage I and II endometriosis is defined by a r-AFS score respectively ranging from 1 to 5 and from 6 to 15. This mild, superficial endometriosis is a very common pathology occurring in infertile women. Nevertheless, these women with stage I/II endometriosis have usually few pelvic pain. This review summarizes the recent literature concerning new data on the pathogenesis of peritoneal endometriosis and its clinical management. Retrograde menstruation, peritoneal adhesion of shed endometrial tissue, and outgrowth of endometrial cells, glands and stroma, are essential elements in the pathogenesis of endometriosis according to Sampson's classic implantation theory. Nevertheless, exact pathophysiology of endometriosis remains unknown. Superficial endometriotic lesions observed by laparoscopy have to be treated. Surgical procedure is not difficult for stage I and II of endometriosis. Surgical procedure remains controversial. Carbon dioxide (CO2) Laser can be used for laparoscopic destruction of endometriosis. Newer procedures, such as SurgiTouch (Lumenis), are more effective in vaporization and decrease the risk thermal damage of contiguous structures. The monopolar scissors can also be used in order to excise the peritoneal endometriotic lesions. Medical treatment may be usefull if surgical treatment is not complete or if the pelvic cavity is hypervascularized. In these cases, Gonadotropin-Releasing Hormone agonists (Gn-RHa) are the most common and effective treatment.