Measles virus causes three distinct neurological syndromes: acute disseminated encephalomyelitis, subacute sclerosing panencephalitis and the rare subacute measles encephalitis, or inclusion body measles encephalitis. There is a current debate of whether subacute measles encephalitis is an opportunistic infection or a subacute infection caused by a mutated measles strain. There is also no report of long term MRI of survivor. We reported a young Chinese girl with a history of relapsed acute lymphoblastic leukaemia and subacute measles encephalitis confirmed by brain biopsy who survived. Serial magnetic resonance imaging of the brain showed cortical and basal ganglial involvement in the initial phase, and generalized cerebral atrophy in the subsequent scan four and a half years later. The patient recovered from subacute measles encephalitis with substantial neurological deficits with the cessation of maintenance chemotherapy without specific antiviral treatment. This suggested that reconstitution of host immunity was adequate in effecting the clearance of the virus, and supporting the hypothesis that subacute measles encephalitis is primarily an opportunistic infection.