Conservative management of at least part of both the ovary and uterus can be proposed in patients with borderline ovarian tumour, in order to preserve fertility potential. This conservative management could be carried out even in patients with borderline ovarian tumour associated with non-invasive peritoneal implants (if complete resection of peritoneal disease has been performed). When facing persistent infertility after this conservative surgery, ovarian induction or an in-vitro procedure could be proposed in patients with an early-stage disease, though the number of attempts must be limited. Removal of the preserved ovary after completion of pregnancy(ies) is unnecessary if patients agree to careful follow-up. In patients with epithelial ovarian cancer, conservative management could safely be performed in young patients who wish to preserve fertility function and who fulfil the following criteria: unilateral tumour (stage IA), grade 1 (and 2?), adequate staging surgery and careful follow-up. Removal of the preserved ovary should be carried out after completion of pregnancy(ies) in order to reduce the risk of ovarian tumour recurrence.