A seventeen year old boy with severe recurrent bacterial infections since infancy is described. Polymorphonuclear leukocytes from the patient were unable to kill certain bacteria after ingestion, whereas other bacterial species were killed normally. The clinical course, studies of leukocyte function and postmortem findings are consistent with a diagnosis of chronic granulomatous disease of childhood. It has been suggested that the abnormality of leukocyte function in this disease is related to failure of degranulation of polymorphonuclear leukocytes. However, detailed studies in the present case provide evidence that degranulation occurs normally. In addition the studies show that macrophages from the patient did not have the same defect and were capable of ingesting and killing bacteria normally. © 1969.