We report a 66-year-old male patient with severe right lower extremity swelling resulting from diffuse pelvic mass with compression on right external iliac vein. The patient had papillary urothelial carcinoma of bladder seven years ago and radical cystectomy and ureterostomy was performed. Recurrence of malignancy had occurred five years after the operation. The patient had also bilateral diffuse lung metastasis. The external iliac vein had severe stenosis and invasion of pelvic mass into the vein was evident on venography. Venoplasty of external iliac vein was performed throughout the stenosis. A venous stent of 80 mm length and 12 mm diameter was introduced over the guidewire and deployed in the external iliac vein. Dramatic clinical response was evident since postoperative day two. Swelling of right lower extremity was resolved dramatically on three-month and six-month follow-up visits. We believe that endovascular venous recanalization of iliac veins is feasible and safe in patients with unresectable and diffuse pelvic masses.