A 4-month-old-girl affected by early expression of Krabbe's disease was treated with allogeneic bone marrow transplantation (BMT). The stem cell donor was her heterozygous HLA-identical mother. The central nervous system (CNS) involvement at diagnosis was evident, but minimal. After BMT the child presented a severe hypotonia and an acute tetraventricular hydrocephalus; she died 180 days after the BMT with progressive severe neurologic deterioration. Leukocyte galactocerebrosidase (GALC) activity was present at donor levels 20 days after BMT. Full donor chimerism was evident 18 days after BMT. This report confirms that in early onset "Krabbe's syndrome" if the diagnosis is delayed after the birth, the progression of the neurologic deterioration is not reversed by BMT. It is to be demonstrated if a very early hemopoietic stem cell transplantation during the first weeks of life, could be appropriate and efficacious.