We report three male patients with aseptic meningoencephalo- radiculitis presenting with acute urinary retention. Viral antibody titers for herpes types I and II and the PCR studies were negative. The cerebrospinal fluid revealed elevated myelin basic protein. The serum antibodies against a panel of gangliosides, some of which are known to be associated with acquired demyelinating neuropathies, were all negative. The magnetic resonance imaging (MRI) studies revealed spotty T2 high intensities in the basal ganglia, thalamus and brainstem in two patients. In one patient,meningeal gadolinium enhancement of the conus and cauda equina of the spinal cord was recognized. On urodynamic studies, all patients showed features of atonic bladder with or without detrusor hyperactivity. They were treated conservatively without using steroids or immunoglobulins, and made a remarkable functional recovery with the disappearance of abnormal MRI findings.However, all three were left with erectile dysfunction, and two continued to use self-intermittent catheterization at more than 3-year follow-up. There was no recurrence of symptoms. The underlying causes remain unclear, though they may represent a variant of acute disseminated encephalomyelitis.