Neurologic, cognitive, and motor outcomes for 36 children with congenital toxoplasmosis treated with pyrimethamine and sulfadiazine for 1 year are reported from Michael Reese Hospital, Chicago, IL, and other Centers. Active infection, seizures, and motor abnormalities resolved in most during therapy. Of 29 infants evaluated at 1 year of age, 23 (79%) had a Mental Developmental Index of 102, and 6 had scores <50. Sibling controls had higher scores than patients, but sequential IQ testing showed no deterioration over time. Six of eight children with obstructive hydrocephalus relieved by shunts had normal neurologic and developmental outcomes. In contrast, of 10 with hydrocephalus ex vacuo from birth, eight had severe disabilities. Nine of 34 (26%) children had microcephaly. Of those presenting with chorioretinal lesions (69%), the majority had residual visual loss after therapy. Risk factors for poor outcome included diabetes insipidus, hypoxia, hydrocephalus with high CSF protein, and delay in medical treatment. These results compared to previous reports for untreated children were thought to justify treatment of pregnant women with acute gestational Toxoplasma infection and young infants with congenital toxoplasmosis. [1]