Critical limb ischemia (CLI) is burdened by a 40% major amputation rate, and a 5-year life expectancy <50%. We report the first in-human injection of lethally γ-irradiated non-human leukocyte antigen (HLA)-matched cord blood (CB)-derived mononuclear cells in a no-option CLI patient, to induce therapeutic neo-angiogenesis, with evidence of successful outcome supported by clinical findings (ulcer healing and pain relief), instrumental assessment (transcutaneous O2 pressure, ankle/brachial index, and contrast-enhanced ultrasonography), and histological demonstration of muscular tissue repair and capillary network expansion. If our approach will be confirmed, the huge number of CB units currently discarded might be redirected toward regenerative medicine purposes, leading to cutting-edge solutions for important unmet clinical needs, such as ischemic diseases, which remain the main cause of disability and mortality in western countries.