The 31 and 81 keV x- and gamma-ray emissions, curie level specific activity, 5 day half-life, and reasonable cost make 133Xe an attractive source for use in cancer implantation therapy. The qualifications of 133Xe as an implantation source, and an analysis of shielding and absorption characteristics are discussed. A method for source fabrication using liquid nitrogen cryo-pumping and heat sealing of plastic tubing is described.