One hundred thirty-three patients with unilateral iliac artery obstruction were treated with crossover femorofemoral grafts and followed up for one to 12 years. Cumulative patency was 73.3% at five years and 63.6% at ten years. There were 17 early closures with ten unsuccessful revisions and 22 late failures between three and 122 months. Inability to establish adequate runoff was the primary cause of early failure, and the progression of distal disease was the major cause of late failures. In only five cases did progressive disease of the donor artery cause failure of the graft. Operative morbidity and mortality were low (6%), and the results compare favorably with alternative methods of treating unilateral iliac artery occlusions.