Chronic granulomatous disease represents a group of disorders of phagocytic cell oxidative metabolism involving recurrent infections with catalase-positive microorganisms and chronic inflammation. Genetic heterogeneity and phagocyte abnormalities, including enzyme deficiencies, abnormal elicited membrane potential changes, abnormal acidification of the phagocytic vacuole, and deficiencies of an electron transport cascade, have been associated with its pathogenesis. In addition, recently we have shown abnormal neutrophil C3b-receptor expression, antibody-dependent cellular cytotoxicity, and abnormal microtubule metabolism (tyrosinolation of the alpha-chain of tubulin). Fourteen patients with the disease who were followed at the National Institutes of Health had life-threatening infections, on average, once every 9.6 months. In most of the 119 febrile episodes seen in these patients, no infectious agent was found. Retrospective studies indicated that prophylactic antibiotic therapy, particularly with trimethoprim-sulfamethoxazole, significantly prolonged disease-free intervals to greater than 40 months (p less than 0.05). In serious, life-threatening infections, leukocyte transfusions have been used in therapy. Transfused leukocytes localize and persist at infectious sites, and the clinical efficacy of leukocyte transfusions has been suggested.