Risk factors for neuroleptic withdrawal dyskinesia in children have not been well studied. The authors present a case of a child who had been treated with a combination of neuroleptics and stimulants for nonpsychotic aggressive behavior. A severe withdrawal dyskinesia precipitated by neuroleptic tapering was ameliorated by discontinuation of the psycho-stimulant. Although stimulants have been reported to increase certain involuntary movement disorders, this is the first known report of psychostimulant exacerbation of withdrawal dyskinesia.