The International Chernobyl Project was launched in 1990 at the request of the Government of the USSR to assess the environmental and health situation in the areas of the Soviet Union contaminated by the Chernobyl accident and to evaluate the measures taken by the authorities to safeguard the health of the population still living in these areas. Some 200 scientists from 25 countries and 7 international and regional organizations participated in this Project. An International Advisory Committee was set up to oversee the Project and approve its conclusions and recommendations. Almost 50 missions to the USSR were carried out in order to obtain the best available information and to make an independent assessment of the situation. The results of the International Chernobyl Project are presented in two main documents: The full Technical Report, which contains, in addition to the conclusions and recommendations of the Project, all the relevant methodologies and the data upon which they are based, and the Overview, which gives a summary of the methodologies presented in the Technical Report together with the conclusions and recommendations. While the Technical Report is intended for the scientific community, the Overview is intended for decision makers, concerned groups and the informed public. Three maps showing the distribution of surface ground contamination by plutonium, strontium and caesium released by the Chernobyl accident and deposited in the Byelorussian SSR, the Russian SFSR and the Ukraine are attached to the Overview. A third document, containing the proceedings of an International Conference which took place in Vienna in May 1991, presents the Project results to the scientific community and to the media. The Proceedings should be read in conjunction with either the Overview or the Technical Report.