Lymphocele formation is a recognized complication of renal allotransplantation that can jeopardize the graft and cause major morbidity for the allograft recipient. Previously, emphasis has been placed on treatment as opposed to prevention. We attempted to prevent lymphocele formation by adopting 2 techniques in performing the renal transplantation: 1) we limited the area of dissection in the recipient to that necessary to obtain vessel control of the segment of iliac vessel that was to be used for the vascular anastomosis (to decrease the number of lymphatics that were divided or destroyed) and 2) we practiced lymphostasis as meticulously as we did hemostasis. We did not attempt to ligate any lymphatics in the hilus of the kidney. Using these techniques we have performed 198 consecutive renal allografts without the development of an identifiable lymphocele. The limitation of the area of vessel dissection has not increased either the rate of major vascular complications (2 per cent) or the development of major pulmonary embolism (0.5 per cent) after transplantation. We conclude that extensive dissection of the iliac vessels is not necessary to prevent major vascular complications or pulmonary emboli after renal transplantation, that careful lymphostasis in the allograft recipient will prevent the development of a lymphocele and, therefore, that the lymph fluid in a lymphocele is derived primarily from the allograft recipient and not from the allograft itself.