Renal dysfunction is a well-known complication following heart transplantation. We examined an early decline in kidney function as a predictor of progression to end-stage renal disease and mortality in heart transplant recipients. We performed a retrospective cohort study of 233 patients who received a heart transplant between July 1985 and July 2004, and who survived >1 month. The decline in estimated creatinine clearance (CrCl) was used to predict the outcomes of need for chronic dialysis or mortality >1-year posttransplant. The earliest time to chronic dialysis was 484 days. A 30% decline in CrCl between 1 month and 12 months predicted the need for chronic dialysis (p = 0.01), all-cause mortality (p < 0.0001) and time to first CrCl </=30 mL/min at >1-year posttransplant (p = 0.02). A 30% decline in CrCl between 1 month and 3 months also independently predicted the need for chronic dialysis (p = 0.04) and time to first CrCl </= 30 mL/min at >1-year posttransplant (p = 0.01). In conclusion, an early drop in CrCl within the first year is a strong predictor of chronic dialysis and death >1-year postheart transplantation. Future studies should focus on kidney function preservation in those identified at high risk for progression to end-stage kidney disease and mortality.