This report was prepared after the Post-Accident Review Meeting on the Chernobyl Accident, Vienna, 25–29 August 1986. A team of Soviet experts who presented a report on the accident at the Chernobyl nuclear power station on 26 April 1986 jointly with INSAG members and other associated experts prepared this agreed report on the accident and formulated recommendations for follow-up actions by the IAEA. Contents: Executive summary; Introduction; 1. The accident at Chernobyl Unit 4; 2. The radionuclide release from the accident; 3. The response at the site; 4. Radiation protection aspects of the accident; 5. Safety issues to be pursued; 6. General observations and provisional conclusions; 7. Recommendations; Annex: RBMK reactors at Chernobyl nuclear power station Units 3 and 4.