Cancer prevalence is high, and of importance to cancer sufferers is the long term survival and normal activities resumption. Moreover, pregnancy is drawing interest for preserving ovarian reserves in post-chemotherapy affected women, especially of younger ages. The gonadotoxic effect of cancer treatment, involves mechanisms that are not fully understood, mainly due to the variety of molecular pathways triggered once therapeutic agents applied. Reported rates of premature ovarian failure after the treatment effect and the application of various treatment protocols, differ extensively due to the protocol itself but also due to the age of treated patients. Several options for preserving ovarian reserves are currently employed in the clinique, such as ovarian transposition, embryos cryopreservation and the use of gonadotropin-releasing hormone (GnRH) and its agonists/antagonists, but most of them are still under investigation. This paper reviews these methods and the molecular mechanisms that are possibly involved in the action of agents such as GnRH.