Chronic granulomatous disease of childhood is characterized clinically by the occurrence of severe and recurrent bacterial and fungal infections. The underlying biologic anomaly is defective microbicidal capacity of phagocytic cells with an abnormal oxidative response during phagocytosis. In most instances, inheritance is recessive and X-linked. Purulent adenitis and skin infections are the most common manifestations, but the overwhelming majority of deaths are caused by pulmonary aspergillosis, abscesses of the liver, and Salmonella infections. The most frequently recovered microorganisms include staphylococci, Aspergillus, Salmonellae, and Gram-negative rods. Bacterial infections seem to be considerably less frequent in patients under long-term prophylactic treatment with the trimethoprim-sulfamethoxazole combination. However, no oral antifungal agent is as yet available for the prevention of pulmonary aspergillosis, as ketoconazole has proved ineffective.