1. In a 20-year period from 1966 to 1986, 650 renal transplants have been performed at the Toronto Western Hospital (University of Toronto). The 10-year actuarial patient survival is 62% and the actuarial graft survival is 35%. 2. A multivariant analysis using the Cox proportional hazard model indicated recipient age, donor source, graft number and time period were factors which independently influenced patient survival and that age and time period were variables which independently effected graft outcome. 3. Sensitization alone, using either peak or current PRA, did not significantly influence graft survival. Sensitization interacting with gender did affect graft survival, which was significantly lower in female patients with a high current PRA. Sensitization interacting with age produced different effects in the younger and older patients. The highly sensitized older patient has a better survival than the highly sensitized younger patient. However, for less sensitized patients the reverse was found; younger patients had a better survival than older patients. Also increasing levels of sensitization correlated with decreased survival in younger patients. 4. Predictive models based on the survivorship analysis of Kalbfleisch and Prentice were constructed to illustrate the impact of these variables on outcome.