Low glomerular filtration rate (GFR) prior to stem cell transplant (SCT) is associated with increased morbidity and mortality. The implications of abnormally high GFRs, or glomerular hyperfiltration, prior to SCT are unknown. Twenty two of 74 consecutive pediatric SCT patients over 2 years old at a single center were hyperfiltrating prior to SCT, median nuclear medicine GFR 154 mL/min/1.73 m ² (IQR 146, 170). There was no association between any demographic and hyperfiltration, nor between hyperfiltration and acute kidney injury ( P = 0.8), renal replacement therapy ( P = 0.63), event-free survival ( P = 1), or chronic kidney disease ( P = 0.73).