Fertility preservation should be considered in girls and young women faced with a potentially gonadotoxic treatment such as chemotherapy. IVF can be performed with the aim to collect and freeze the oocytes, or ovarian tissue can be cryopreserved and transplanted back to the patient at a later stage. Whichever method is chosen depends upon the age of the patient, the gonadotoxicity of her treatment and the time frame. It is important to refer young cancer patients to fertility preservation counselling before treatment starts, as argued in this review.