Acute leukaemia is a life-threatening disease that needs treatment without delay. Fertility preservation is recommended, but often not possible because of the necessity to start treatment as soon as possible. The present study is a retrospective single-centre analysis of 459 patients diagnosed with acute leukaemia between 2002 and 2012. Sperm or oocyte preservation was successfully performed in only 29 (6%) patients. Of the 150 children, no paediatric patient sample was taken. The collected samples enabled the conception of 2 children by in vitro fertilisation; in addition, 3 spontaneous, non-assisted births in partners of male patients were observed. Fertility preservation is important but difficult to accomplish in patients with acute leukaemia; more efforts are clearly needed to preserve fertility in long-term survivors of acute leukaemia.