Methylphenidate is the psychotropic drug most commonly used to treat individuals suffering from developmental attention-deficit-hyperactivity disorder. Additional attention deficit is part of numerous neurologic diseases in childhood. Despite the vast extent of scientific research on methylphenidate, the use of this stimulant in the treatment of cognitive and behavioral dysfunction in children with epilepsy, brain tumor, leukemia, closed brain injury, encephalitis, meningitis, or mental retardation continues to be controversial. Only few data exist about the efficacy and side effects of methylphenidate treatment in children with this neurologic illness or history. The aim of the present study is to provide a review of this important clinical topic and perhaps to stimulate further controlled investigations.