Agranulocytosis has been reported as occurring from infancy on through all age groups. However, we have been unable to find any reports of agranulocytosis of a newborn infant. In 1933 Givan and Shapiro1reviewed the cases of 2 infants, aged 10 and 12 weeks, with agranulocytosis. Ten years later Kato2reported the case of an 8 week old infant, in whom agranulocytosis developed during treatment with sulfathiazole. We present the history of a newborn infant who was found to have agranulocytosis on his third day of life. REPORT OF CASE M. C., a white male infant, was born on April 15, 1948, weighing 6 pounds 13 ounces (3,089 Gm.) and measuring 19.5 inches (49.5 cm.) in length. The mother was 38 years of age. She had been pregnant twice but had carried no other child to term. The Wassermann reaction was negative, and her blood was type O