The atmospheric transport to Sweden and the deposition there of radioactive material following the Chernobyl accident have been described on the basis of radiological and meteorological data and theoretical calculations of despersion. The radioactive cloud created by the explosion at 01. 23 local time on 26 April 1986 was transported north- west and north over the Baltic Sea. An extensive long-distance transport of radionuclides to Scandinavia and Finland took place. Sweden was affected by dry deposition, including fairly large hot particles and also by wet deposition. Wet deposition occurred in connection with precipitation over eastern Sweden on 28 April, which further affected parts of northern Sweden until 30 April. Deposition of caesium mainly occurred through wet deposition. In the case of certain other radionuclides, including 95Zr and 239 Np, a considerable part of the deposition occurred in the form of dry deposition. The study has attempted to estimate the probabil ity of Sweden being affected to a similar extent following a major nuclear accident outside the country's borders.