Cyr61 is a secreted, cysteine-rich heparin-binding protein that is associated with extracellular matrix and cell surface, and has been demonstrated to be proangiogenic in vitro. In the present study we evaluated the angiogenic effect of human Cyr61 in an adenoviral context in the rabbit ischemic hindlimb model. For this purpose, three randomized groups of New Zealand White rabbits received intramuscular injections of 5 x 10(8) infectious units of an adenovirus carrying either the Cyr61 gene (Ad-Cyr61), the vascular endothelial growth factor gene (Ad-VEGF(165)) used as the angiogenic gene of reference, or no transgene (Ad-Null), 10 days after femoral artery excision in one limb. Perfusion of the ischemic limb was evaluated before adenoviral treatment (day 10) and 30 days postinjection (day 40). Angiographic, hemodynamic, and histologic parameters indicated that animals in the Ad-Cyr61 group had significantly better perfusion than in the Ad-Null group. Interestingly, this improvement exceeded that achieved with Ad-VEGF(165). In conclusion, Cyr61 gene transfer appears potent in stimulating limb revascularization, thereby promoting great improvement in tissue perfusion in the ischemic limb. These findings indicate that Cyr61 could be a promising therapeutic candidate for treating severe peripheral ischemic diseases.