The literature contains contradictory results related to the effects that allografts that are not perfectly size-matched have on long-term renal graft function. Authors who accept hyperfiltration as the non-immunologic mechanism that leads to chronic graft loss recommend against using small-for-size kidneys. On the other hand, it is known that pediatric recipients are more prone to hypertension. The aim of this study was to compare early-postoperative scintigraphic findings in pediatric and adult recipients of adult kidneys using Tc-99m DTPA renal scintigraphy. This study included 20 pediatric and 20 adult recipients of adult kidneys. Tc-99m DTPA renal scintigraphy was performed on postoperative day 7. Early postoperative course of all recipients were uncomplicated. Images were acquired every second for the first minute (perfusion evaluation) and then every 30 seconds for 20 minutes (function evaluation). The following parameters were computed: the ratio of peak activity at perfusion to peak uptake on the graft curve (P:U), time to maximum uptake (Tmax), glomerular filtration rate (GFR), and activity retained at 20 minutes (R20). The pediatric patients had a significantly longer mean Tmax and a significantly lower mean P:U than the adult recipients (p<0.05 for both). The children also had a lower mean GFR (p>0.05) and a slightly higher mean R20 (p>0.05). The results indicate that the early-postoperative scintigraphy findings in pediatric and adult recipients are significantly different. The longer Tmax and a lower P:U in pediatric recipients may suggest absence of capacity for future hyperfiltration or relative hypoperfusion considering the size of the adult kidney. Long-term effect of these findings in relation chronic allograft loss needs to be determined.