The Medical Research Council's AML 10 Children Trial commenced in 1988. It is a multicentre collaborative study based on 4 courses of intensive chemotherapy with additional allogeneic bone marrow transplantation for children with a matched sibling donor. The remaining children are randomised either to an autologous transplant using unpurged marrow or stopping therapy. To date 156 eligible patients have been entered with a CR rate of 91%. 56% of children are still alive 2 years after trial entry and 57% are in CR 3 years after achieving CR. The treatment regimen is intensive but mortality and morbidity are acceptable. The study will need to accrue patients for a further 2 to 3 years in the hope of defining the role of allogeneic and autologous marrow transplantation.