Results in 355 Cs-treated renal graft recipients have been analyzed. The majority of graft losses occurred early. Prior sensitization and repeat grafts were clear-cut early risks for cadaver recipients but not live-related donor grafts. In neither group was presensitization clearly a risk factor for late losses, although repeat grafts were much more at risk late. The majority of late losses was due not to chronic rejection but to deaths from cardiovascular disease and cancer, and a surprisingly high number from noncompliance.