A multicentre, randomized clinical trial of antilymphocyte globulin (ALG) was conducted among patients who had undergone cadaver kidney transplantation; follow-up was continued for a minimum of 1 year. Of the 179 patients 92 were given conventional treatment only, while 87 were given in addition ALG (from a standardized, highly immunosuppressive, common pool of equine ALG), 20 mg/kg-d intravenously for 10 days after transplantation. The ALG-treated group had better accumulated graft survival, fewer nephrectomies, better graft function, less than half the number of acute rejection episodes and less prednisone use. There was a beneficial drug (ALG)-related effect in both the graft and the host during the first 3 months after transplantation.