Meningitis is the most common central nervous system complication of mumps virus, whereas encephalitis, cranial nerve palsies, poliradiculoneuritis are less common and myelitis caused by mumps virus is very rare [Nussinovitch et al., Acta Pediatrica (1992) 81, 183]. Lesions in young age as a result of severe acute transverse myelitis [shown on a magnetic resonance imaging (MRI) procedure] often has a viral cause. The case of a young male afflicted by meningoencephalomyelitis because of mumps virus is discussed.