The symptom complex of ipsilateral leg swelling, leg pain, pelvic fullness and decreased renal function in a renal transplant recipient coupled with roentgenographic demonstration of an extrinsic mass compressing the urinary bladder and perhaps obstructing or displacing the transplant kidney ureter, is almost diagnostic of a lymphocele. Impaired renal function, thrombophlebitis and subsequent pulmonary embolism are severe complications of lymphoceles. The treatment of choice appears to be external drainage for primary lymphoceles and intraperitoneal marsupialization for recurrent lymphoceles.