Subacute sclerosing panencephalitis (SSPE), an insidiously progressive slow viral infection of the central nervous system caused by the mutated measles virus, is invariably fatal. Various medications have been tried unsuccessfully till date with rare remissions. A case of 21-year woman with adult-onset SSPE who improved after treatment is reported. She had seizures, psychosis, and extrapyramidal symptoms and was on multiple anti-seizure medications without response. She was given a trial of levamisole with gradual escalation and achieved complete clinical remission by 21 months. This case demonstrates the curative potential of levamisole in adult-onset SSPE. A review of previous treatments attempted in cases who underwent remission of SSPE is also presented.