A canine model of end-to-end anastomosis between the iliac arteries and polytetrafluoroethylene grafts was developed; a self-expanding Wallstent was placed across one anastomosis. The opposite limb acted as a control. Animals were killed at 4 or 12 weeks. Sections were taken and the intimal thickness and luminal area calculated. At 12 weeks intimal thickness was significantly greater at anastomoses in control sections (P = 0.007), and at the interface between the proximal stent and graft in stented graft limbs (P = 0.01). Control graft limbs had significantly enhanced intimal thickness at the anastomotic level at 12 weeks compared with that at 4 weeks (P = 0.0002), while there was no such increase for the stented side. There was no significant difference in luminal area between control and stented graft limbs. Anastomotic neointimal hyperplasia in a canine graft-artery bypass model is modified by endovascular stenting.