With improvements in short-term kidney graft survival, focus has shifted towards long-term survival. There has also been a substantial improvement in long-term survival as measured by kidney half-life. Long-term graft failure is secondary to chronic allograft nephropathy (CAN), recurrent disease, and death with a functioning graft. CAN is secondary to a combination of chronic rejection, chronic cyclosporine toxicity, and/or donor kidney disease. Risk factors for chronic rejection have been attributed to both immunological and nonimmunological causes. With a marked reduction in acute rejection rates-an important risk factor for CAN-there is a substantial improvement in kidney half-life. There are still nonimmunological factors, such as donor age, that adversely affect long-term graft survival. In addition, African-American recipients continue to have a shorter graft half-life. Recurrent disease is becoming an important cause of late graft failure. Despite the introduction of various potent immunosuppressive agents, there has been little or no impact on the prevalence as well as progression of recurrent diasease. With the reduction of acute rejection rates and improved short- and long-term graft survival, further improvements of long-term graft survival will be an important focus in the 21 st century. (C) 2001 by the National Kidney Foundation, Inc.