Studies in the renal transplant population have suggested calcium-channel blockers (CCBs) may protect against calcineurin inhibitor (CNI)-induced nephrotoxicity. However, this has not been evaluated in the hematopoietic stem cell transplant (HSCT) population. This retrospective study reviews data from 350 consecutive patients who underwent allogeneic HSCT to determine whether amlodipine improved renal outcomes. Subject data included up to one year from CNI initiation. Patients in the amlodipine group (n = 130) received an average of 143 days treatment with amlodipine and experienced a smaller decrease in creatinine clearance (CrCl) through day 180. At day 30, change in CrCl was -17.4 mL/min in the amlodipine cohort and -33.8 mL/min in the control (P < 0.001). At day 180, change in CrCl was -40.9 and -50.6 mL/min, respectively (P = 0.005). Incidence of hospitalization with acute kidney injury (AKI) was significantly lower in patients receiving amlodipine, 7.7% (10/132) vs 16.4% (36/220) (hazard ratio [HR] 0.44; 95% confidence interval [CI] 0.22-0.89). Median blood pressure in the amlodipine group remained