Neovascularization is a physiological repair process that is partly dependent on nitric oxide. Extracellular superoxide dismutase (EcSOD) is the major scavenger of superoxide and thus is an important regulator of nitric oxide bioavailability and thus protects against vascular dysfunction. We hypothesized that overexpression of EcSOD in skeletal muscle would improve recovery from hind-limb ischemia.