This article presents data on the diagnosis and phenomenology of schizophrenia in 16 hospitalized children, ages 5.5 to 11.75 years. These 16 subjects are the first to complete an ongoing double-blind, placebo-controlled study of haloperidol in children with schizophrenia diagnosed by DSM-III-R criteria. We describe the pharmacologic treatment response of this subsample and compare our diagnostic, phenomenologic, and treatment findings with those of other investigators. Our results show that children under age 12 can be diagnosed with schizophrenia by the same criteria used for adults, that they show comparable clinical symptoms, and that on haloperidol they show improvement in target psychotic symptoms, at least in a short-term inpatient setting.