Mumps is an acute viral illness, which presents with glandular and/or nervous system involvement. The most common central nervous system manifestations of mumps include aseptic meningitis and meningoencephalitis. Mumps meningoencephalitis, which is characterized by fever, vomiting, nuchal rigidity, and altered sensorium, usually develops at least 3-10 days after mumps parotitis. Acute hydrocephalus secondary to mumps meningoencephalitis is rare. Here we report a child who developed acute hydrocephalus following mumps meningoencephalitis and who was treated with external ventricular drainage following which he showed exceptional recovery.