Cerebral abscess occurring in patients with congenital disease of the heart is rare and not commonly recognized. There are early recorded observations of cerebral abscess in patients dying with congenital heart disease, but it was not until 1880 that Ballet1first made clear the relationship of these two morbid conditions. The incidence of congenital heart disease varies considerably in the necropsy observations reported from different institutions. For example, 75 cases of this anomaly reported by Leech2from the Johns Hopkins Hospital constituted 1.29 per cent of all the cases in which necropsy was done, whereas the 105 cases of congenital anomalies of the heart or the great vessels reported by Gibson3from the cardiac service of the Children's Memorial Hospital were 5.4 per cent of the 1,950 cases of infants on whom autopsy was performed. Cerebral abscess as a complication is not mentioned by either author. All