Computer-assisted renal scintigraphy was performed on 160 acute and 240 chronic spinal cord injury patients, and 287 noninjured controls. Concurrently, measurements of global and individual kidney effective renal plasma flow, time of maximum activity in each kidney, ratio of maximum counts to the counts at 27 minutes after injection over each kidney and number of counts in each kidney at 1 to 2 minutes after injection were made. The time of peak activity over the kidney and differential function at 1 to 2 minutes after injection were not affected significantly by age, sex or spinal cord status. Global and individual effective renal plasma flows were significantly affected by all of these factors. Both plasma flow measures generally were higher for male than for female patients. Effective renal plasma flow decreased steadily after early adulthood and, except for the youngest and oldest patients, values were lower for spinal cord injury patients than for normal controls. The ratio of peak to 27-minute counts was affected significantly by age and spinal cord injury but not by sex. In patients without obvious pathological conditions followup scintigrams 1 to 3 years after injury showed no significant changes owing to interval since injury on any parameter studied. Lower limits of basal scintigraphic parameters are given for evaluation of renal status in neurologically intact or spinal cord injury persons.