Chronic granulomatous disease is a rare, genetically heterogeneous group of disorders in which NADPH oxidase deficiency severely hampers the ability of phagocytes to kill ingested microorganisms. Characterized by recurrent pyogenic infections with granuloma and abscess formation, the disease appears in childhood and may be fatal. Conventional therapy consists of prophylactic trimethoprim-sulfamethoxazole and aggressive infection control measures. Interferon-gamma (IFN-gamma) has been shown in vitro and in vivo to correct alterations of oxidative metabolism. In the most recent multicenter study, IFN-gamma was efficacious in reducing the frequency of severe infections; however, at odds with previous results, this effect appeared to be due to some mechanism other than improvement in respiratory burst function. Although further studies are needed to elucidate the mechanisms of IFN-gamma's action, it appears to have potential application in many infectious diseases.