The increased incidence of tumors in children and adolescents (Lacour, 2010), as well as therapeutic advances in recent decades, have led to an increase of fertility disorders in young adult cancer survivors. In pubescent boys, the use of cryopreserved sperm and assisted reproductive technology (ART) is a validated preventive option. Currently, there is no consensus on the age at which the semen cryoconservation has to be proposed. There is a wide disparity of care among centers in France. Based on the observation of Nathan,11 years old, in whom semen cryopreservation was performed at his request, we analyze local practices and discuss the indications for cryopreservation of sperm in young teenagers with cancer treated by potentially sterilizing treatment.