Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that stimulates angiogenesis during tissue ischemia. In vivo electroporation (EP) enhances tissue DNA transfection. We hypothesized that in vivo EP of plasmid DNA encoding a constitutively expressed HIF-1α gene enhances neovascularization compared with intramuscular (IM) injection alone.