Purpose: Renal scintigraphy (RS) with either technetium-99 m diethylene-triamine-pentaacetate (Tc-99 m DTPA) or technetium-99 m mercaptoacetyltriglycine (Tc-99 m MAG3) has both been used to evaluate early allograft function after kidney transplantation (KT). This study was done to compare the predictive performance of RS using these two radiopharmaceuticals for prediction of outcomes during first 3 months of KT. Methods: This retrospective study included patients who received KT then underwent both Tc-99 m DTPA and Tc-99 m MAG3 RS, successively. Receiver operating characteristic (ROC) curve analysis was used to determine the predictiveness of RS parameters on early clinical adverse outcomes of either (1) graft-related death, (2) need for graft resection, (3) delayed graft function requiring temporary dialysis, or (4) a serum creatinine level of ≥ 2.0 mg/dL at three months post-KT, as well as to predict biopsy-confirmed acute tubular necrosis and acute rejection. Results: Of 187 patients included, 77 (41.2%) had at least one early adverse clinical outcome. Tc-99 m MAG3 RS was more predictive than Tc-99 m DTPA RS, in terms of AUCROC, in three parameters including time to peak (0.754 vs. 0.516, p-value 0.0001), 20-min to peak ratio (0.762 vs. 0.651, p-value 0.006), and 20-min to 3-min ratio (0.823 vs. 0.699, p-value 0.0005). Acute tubular necrosis was better predicted by Tc-99 m MAG3 RS while both were at best only modest in predicting acute rejection. Conclusion Three parameters which, when obtained from Tc-99 m MAG3 RS, had superior predictiveness compared with Tc-99 m DTPA RS, including time to peak, 20-min to peak ratio, and 20-min to 3-min ratio.