Progressive multifocal leukoencephalopathy (PML) is related to central nervous system infection with JC virus (JCV). This leukoencephalopathy occurs in immunocompromised patients such as those with acquired immunodeficiency syndrome (AIDS) or lymphoid malignancies. We describe here a patient with myelodysplastic syndrome who developed several life-threatening infections including listeriosis, tuberculosis, and PML. Listeriosis and recurrence of tuberculosis preceded the occurrence of PML. Neurologic features associated with major ataxia, speech disorders, and PML were documented by cranial magnetic resonance imaging showing typical features in the cerebellum and proven by polymerase chain reaction (PCR) detection of JCV DNA in the cerebrospinal fluid. No specific treatment was decided because of progression toward acute myeloid leukemia. In this case, PML occurred with no susceptibility and without immunosuppressive treatment. Our case adds further support to the association between the impairment of T-cell immune responses and myelodysplastic disorders.