The current therapeutic angiogenesis strategy to treat ischemic disease by using angiogenic growth factors has been limited to use of a single gene. However, as vasodilator substances such as prostacyclin are widely used for the treatment of peripheral arterial disease, it might be useful to combine angiogenesis with vasodilation of new vessels. In a mouse hind limb ischemia model, cotransfection of the hepatocyte growth factor (HGF) gene with the prostacyclin synthase gene demonstrated a further increase in blood flow and capillary density compared with a single gene. Even in the rabbit ischemia model, cotransfection of HGF plasmid with the prostacyclin synthase gene demonstrated a further increase in angiogenic activity compared with HGF alone. Because peripheral neuropathy due to diabetes is common for significant morbidity, we examined the hypothesis that experimental diabetic neuropathy can be reversed by HGF and prostacyclin synthase genes. Severe peripheral neuropathy, characterized by significant slowing of nerve conduction velocity compared with nondiabetic control animals, was ameliorated. Overall, cotransfection of the prostacyclin synthase and HGF genes is more effective than single-gene transfection to stimulate angiogenesis, and it significantly improved neuropathy. These data provide important information relating to the clinical application of therapeutic angiogenesis to treat peripheral arterial disease.