Results of 140 combined first-pass and dynamic functional renal studies were clinically evaluated in 50 patients with a transplanted kidney. The renal handling of three different nephroaffine radionuclides, namely the glomerular agent (99m Tc-DTPA), the predominantly tubular agent (99m TcMAG3) and combined glomerulo-tubular agent (99m Tc-PAHIDA) was also analysed in various dysfunctions of renal transplants. It has been concluded, that the clinically most useful information at all levels of the overall renal function has been given by 99m TcMAG3. However, the behaviour of glomerular and tubular agents in postischaemic acute tubular lesion was found to be discordant which in turn could be valuable differential-diagnostic information, and out of this reason their successive application is essential. The combined firstpass and dynamic functional renal studies have been judged as a helpful diagnostic tool in the follow-up of patients who have undergone kidney transplantation, provided that its results are interpreted in the light of clinical and other relevant findings.