Male siblings developed acute hemorrhagic leukoencephalitis (AHL) at age five months and eight months, respectively. This rare condition has not been reported in individuals less than two years of age or with a recurrence in the family. The diagnosis was based on neuropathologic features after ruling out potentially mimicking conditions. Genetic counseling of early onset AHL should include the possibility of recurrence in siblings. © 2001 Wiley-Liss, Inc.