Bogomolov VV, Castrucci F, Comtois J-M, Damann V, Davis JR, Duncan JM, Johnston SL, Gray GW, Grigoriev AI, Koike Y, Kuklinski P, Matveyev VP, Morgun VV, Pochuev VI, Sargsyan AE, Shimada K, Straube U, Tachibana S, Voronkov YV, Williams RS. International Space Station medical standards and certification for space flight participants. Aviat Space Environ Med 2007; 78:1162–9. Introduction: The medical community of the International Space Station (ISS) has developed joint medical standards and evaluation requirements for Space Flight Participants (“space tourists”) which are used by the ISS medical certification board to determine medical eligibility of individuals other than professional astronauts (cosmonauts) for short-duration space flight to the ISS. These individuals are generally fare-paying passengers without operational responsibilities. Material and Context : By means of this publication, the medical standards and evaluation requirements for the ISS Space Flight Participants are offered to the aerospace medicine and commercial spaceflight communities for reference purposes. It is emphasized that the criteria applied to the ISS spaceflight participant candidates are substantially less stringent than those for professional astronauts and/or crewmembers of visiting and long-duration missions to the ISS. Conclusions: These medical standards are released by the government space agencies to facilitate the development of robust medical screening and medical risk assessment approaches in the context of the evolving commercial human spaceflight industry.