Fertility Preservation is now considered as crucial for the well-being of women battling cancer. However, others indications have more recently emerged. Women with endometriosis may represent a suitable group since they are at risk for compromise ovarian reserve. Data on FP in endometriosis patients are rare: only small retrospective study, case-reports and opinion publications .Nowadays, there is no available data concerning real indications for PF on endometriosis patients (endometriomas, risk of surgery, deep endometriosis?), criteria for eligibility (ovarian reserve parameters, age), quality of oocytes and number of oocytes necessary to give at least one live birth. We propose a monocentric observational cohort study, evaluating the efficacy of oocytes cryopreservation as fertility preservation procedure, in young adult female subjects with endometriosis, to finally define the criteria of eligibility for PF procedures in case of endometriosis.