A patient with a traumatic femoral arteriovenous fistula was misdiagnosed for 11 years as having "postphlebitic syndrome." Angiography revealed diffuse dilatation of the veins and arteries of the right lower extremity with the iliac vein measuring 16.0 cm in diameter and the cava 6.0 cm in diameter. Operative repair of the fistula has resulted in marked clinical improvement and return of the patient to fulltime employment. A history of trauma should be sought when a patient presents with unilateral chronic venous insufficiency.