We report the case of a 25-year-old man who underwent successful en-bloc resection of a retroperitoneal fibromatosis, extended to the right kidney and testis, with excision of the right iliac arteries and veins. Arterial replacement was done by means of a right iliofemoral prosthetic graft. A right femorocaval prosthetic graft with a temporary arteriovenous fistula was used for venous replacement. The patient is still alive and after 3 years shows no sign of recurrence on successive computed tomographic scans. He has preserved patency of the right arterial and venous iliac grafts. To our knowledge, this is the first documented case of simultaneous arterial and venous iliac replacement successfully performed after excision of a retroperitoneal tumor.