Twelve of the 25 patients with chronic granulomatous disease treated at our institution between 1957 and 1987 were found to have urinary tract disorders. All 12 patients were male and 22 years of age or younger when chronic granulomatous disease was diagnosed. Six patients had hydroureteronephrosis in association with recurrent episodes of pyelonephritis, retroperitoneal lymphadenitis, and granuloma formation. The other six patients had genital lesions or dysuria. Among the six patients with hydroureteronephrosis, a nephrectomy was performed in two, ureterolysis was used to relieve obstruction in one, and hydroureteronephrosis resolved after antibiotic therapy alone in three. We conclude that complications involving the genitourinary system occur frequently in patients with chronic granulomatous disease. Periodic imaging of the urinary tract may detect asymptomatic hydroureteronephrosis or other treatable genitourinary abnormalities in these patients.