The CNS involvement by leukemia may either be meningeal or parenchymal, although meningeal infiltration of leukemic cells, known as leukemic meningitis is more common. We report a case of leukemic meningitis involving the cauda equina in a patient with an acute lymphoblastic crisis which transformed from the chronic phase of chronic myeloid leukemia. An MR image revealed diffuse enlargement and peripheral ring enhancement of the nerve roots of the cauda equina.