We located 59 persons with spinal cord injury (SCI) who had not been examined for 3-15 years and paid them to undergo evaluation and comparison with 101 controls examined on an annual basis. Renal function during the first year post-injury and at follow-up was measured by radioisotopic scanning to determine effective renal plasma flow (ERPF) and information was obtained regarding occurrence of specific secondary complications. Subjects and controls were alike with respect to demographic characteristics, injury-related variables and occurrence of specific secondary complications. Mean initial and follow-up ERPF values adjusted for increasing age were not significantly different for subjects and controls, nor was there significant change within individuals over time. Although serial examination of the urinary tract following SCI is important, after the first few years it may be acceptable to lengthen the periods between examinations or substitute less expensive, noninvasive diagnostic techniques. SCI care centers should carefully evaluate recommendations regarding follow-up urologic examinations in persons with SCI in order to provide the most cost-effective program while maintaining optimum patient care.