This study is a multifactorial analysis of 389 transplants performed from June 1977 to December 1981. Analysis of the effects of transfusions antilymphocyte serum (ALS), histocompatibility testing, gender, and patient risk factors (presence of concomitant disease, greater than 50 years of age, etc.) was done. Two-hundred fifty-three patients received cadaver kidneys and 136 patients obtained kidneys from a relative. Two-hundred eighty-three (73%) patients received blood transfusions prior to transplantation. Our data showed that recipients receiving transfusions prior to transplantation had a significantly higher graft survival than those who were not transfused in both cadaveric and related graft recipients. Two-hundred twenty-one (56%) patients received ALS following the transplant. This group had a 15% higher graft survival than a comparable group. Analysis of histocompatibility testing data shows approximately 5% higher functional graft survival between each match grade. Surprisingly, female patients receiving kidneys from living related donors had a 16% higher graft survival than male patients. In cadaver recipients female patients had a 10% higher patient survival as compared to male patients. The risk factor status of recipients affected not only graft survival but patient survival, which probably is due to the consequences of immunotherapy. The authors' conclusion is that the above mentioned factors may be additive in nature. Further, multivariable analysis is necessary in order to correctly transplant data.