The neurological examination of many hyperactive children reveals the presence of abnormal neurological signs. Of 40 hyperactive children who had three or more neurological abnormalities on an initial neurological evaluation, 29 (72.5%) showed marked improvement or complete resolution of the neurological signs following treatment with methylphenidate hydrochloride (Ritalin) for 60 days. The administration of placebo did not change appreciably the neurological status of 20 hyperactive children. Improvement in behavior, which was ascertained by the use of Conners' Abbreviated Teacher Rating Scale, did not always correspond with resolution of the abnormal neurological signs. This finding suggests that methylphenidate affects behavioral and motoric functions separately and independently. Repeat neurological assessment, looking for resolution of abnormal neurological signs, should be included as part of the follow-up medical examination in treated hyperactive children. Coupled with other objective and subjective test information, improvement of the neurological status provides supportive evidence of overall improvement in the hyperactive child who is receiving drug therapy.