The improved survival rates among patients with haematological malignancies, such as lymphoma and leukaemia, are shifting areas of focus towards understanding and preventing treatment-induced sequelae. Of these, infertility is one of the most devastating consequences for patients with reproductive potential. The degree of treatment-induced gonadal dysfunction depends on age and gender-related differences, the type and dosage of chemotherapy used and the field and cumulative dose of abdomino-pelvic irradiation. There is also the interesting phenomenon of reduced pre-treatment fertility among male lymphoma patients. At present, the only established methods of fertility preservation are cryopreservation of sperm, oocytes and embryos, as well as gonadal shielding and transposition of ovaries during irradiation. Several other methods, such as cryopreservation and subsequent transplantation of gonadal tissue and the gonadoprotective role of hormonal suppression, are under investigation. Pre-pubertal patients present a unique constellation of fertility considerations, especially as embryo and sperm cryopreservation are not applicable to this age group.