This article offers the first scholarly account of the International Sakharov Hearings, which were prompted by the so-called Moscow Appeal (1974) and took place in Copenhagen (1975), Rome (1977), Washington, DC (1979), Lisbon (1983), and London (1985). The article provides a detailed examination of each hearing, from the amateurish and politically murky origins in Copenhagen to the more mainstream and quite successful event in London. The article also attempts an overall assessment of the hearings as an original, important case of an international citizens’ tribunal resulting from transnational human rights activism pursued in Andrei Sakharov's name in the context of the Helsinki process. It raises questions about the roles played by various individuals, networks, and agencies, as well as the possible impact of the hearings, both domestically and internationally.