The results of 20 HLA 1-haploidentical donor kidney transplant patients treated with preoperative lymphocyte deletion through thoracic duct drainage and low dose of cyclosporine and steroid immunosuppressive therapy, were presented. The number of removed lymphocytes was 114 +/- 36 X 10(9) (mean +/- SD) and the duration of thoracic duct drainage was 35 +/- 7 days. Graft survival was 100% at 3-9 months and 89% at 1-2 years after transplantation. Patient survival was 100% at 3-9 months and 89% at 1-2 years. A patient died from lung cancer (adenocarcinoma) in the 9th posttransplant month. Acute rejection was not seen in 20 patients during the first 3 months. Life-threatening infectious disease was never seen either. Diabetes mellitus was observed in 1 patient. No other complications were observed. These results indicated that thoracic duct drainage and low dose cyclosporine and steroid postoperative immunosuppressive treatment might yield complete success in HLA 1-haploidentical kidney transplant patients.