Background: The evaluation of individual renal function is important to diagnosis and follow-up of various diseases. Ureteral catheterization of each kidney has been widely used for this purpose, but this method had some technical difficulty, frequent complications and much restriction in reapplication. Therefore we tried to applicate radiopharmaceuticals for the evaluation of individuai renal function. Methods: We measured 2 hour, 4 hour and 24 hour relative renal uptake of 99mTc-DMSA and relative glomerular filteration rate of 99mTc-DTPA with 59 patients with various renal diseases to determine their usefulness for assessment of individual renal function and to compare correlations between every renal uptake of Tc-DMSA and relative glornerular filteration rate. Results: The correlations between 2 hour-, 4 hour- and 24 hour- relative renal uptake of 99mTc-DMSA and relative glomerular filterat.ion rate of 99mTc-DTPA were R=0.9190 (p<0.001), R=O. 9229 (p<0.001) and R=0.9917 (p<0.001). In acute obstructive uropathy, the correlations at 2 hour and 4 houre were poor as R=0.1812 (p<0.05) and R=0.4923 (p<0.05), but the correlation at 24 hour was good as R=0.9942 (p<0.001). Conclusions: We concluded that relative renal uptake at 2 hour and 4 hour had good correlation with relative DTPA uptake ratio in the cases without chronic renal failure and obstructive uropathy. Delayed image with 24 hour relative renal uptake of 99mTc-DMSA had the best correlation with relative glomerular filteration rate of 99mTc-DTPA and that might be useful in evaluation of chronic renal disease in which showed increased beckground activity or acute obstructive uropathy.