While neurocognitive impairments in attention, memory and executive functioning are commonly reported sequelae of childhood leukemia and brain tumors, studies have only recently begun to examine the treatment of attention deficits in this population. Numerous studies have examined the effectiveness of methylphenidate in the treatment of children with attention deficit hyperactivity disorder (ADHD). However, the effectiveness of this medication for improving attention and behavioral functioning in children with medical illnesses or brain injury are less clear.