A membership seeking policy was condemned to failure in the first two attempts (1961-63 and 1970-72) that Portugal made to join the former European Economic Community (EEC), mainly for a reason: the non-democratic nature of the Portuguese regime. In 1977, Portugal applied again to become a full member of the EEC. But this time a democratic revolution had preceded it. This paper contributes to the comprehension of the linkage between democracy and accession to the EU. This paper aims therefore to assess what was the role that the democratic principle, acknowledged at several political reports and enshrined at the Treaty of Rome, played in the Portuguese accession negotiations to the EEC.