The effect of stimulant medication on the attentional functioning of 23 children (8-12 yrs) with attention deficit/hyperactivity disorder (ADHD) was investigated. Significant main effects of medication and TEA-Ch subtests were found, however there was no significant interaction. Planned contrasts showed that stimulants improved performance on the sustained attention, but not the selective or divided attention, subtests. Similar to previous studies, the results indicate that stimulants improve sustained attention in children with ADHD. Significant effects of stimulants on selective and divided attention, however, were not as apparent. Therefore, care must be taken when using TEA-Ch subtests to assess performance change subsequent to stimulant administration.