BACKGROUND Chronic granulomatous disease (CGD) is characterized by defective bactericidal activity of white blood cells, specifically, a defect in superoxide production. Patients experience infections, predominantly caused by catalase-positive bacteria and fungal organisms, that may be severe and life-threatening. Most cases of CGD are diagnosed in children; however, it may rarely go undiagnosed until adulthood in individuals with unexplained infections and granulomatous inflammation. OBJECTIVE To describe an adult with Crohn disease and recurrent infections who was newly diagnosed as having CGD. METHODS A 53-year-old woman with a history of liver abscesses and Crohn disease presented with Burkholderia cepacia pneumonia and required a right middle lobe resection. Nitroblue tetrazolium test results confirmed the diagnosis of CGD, and Western blot analysis revealed the absence of the 47-phagocyte oxidase protein. Levels of Crohn-associated specific antibodies to Saccharomyces cerevisiae and Escherichia coli outer membrane porin C were elevated. RESULTS The patient, newly diagnosed as having CGD, was given intravenous trimethoprim-sulfamethoxazole, after which she improved clinically and was discharged from the hospital in stable condition to receive daily oral trimethoprim-sulfamethoxazole treatment. CONCLUSIONS The concomitant occurrence of Crohn disease and CGD, both characterized by granulomatous inflammation, is noteworthy. This case study demonstrates that CGD should be considered in adults with recurrent infections, especially those caused by catalase-positive organisms, such as B cepacia.