Résumé : A 7-month-old boy with a high risk ALL harbouring the translocation (4;11) was grafted with an haploidentical bone marrow from paternal origin. At time of relapse, 11 months after BMT, he received donor leukocyte infusions (DLI) which put him in second CR. GVHD and pancytopenia occurred 2 weeks after DLI and were fully reversed with CsA + prednisolone. Six months later, the child continues to be in second CR, off steroid therapy, without any signs of GVHD. Our limited experience indicates that a second CR can be obtained with acceptable toxicity by DLI in very high risk ALL children who have been previously grafted with haploidentical bone marrow cells.