The Council of Europe, established on 5 May 1949, has been based since its inception on a community of values, in particular a community of law, attempting to harmonize the law of the member states around common principles, which include the principles of democracy, the rule of law and respect for human rights. These principles are complementary to each other, as none of them can be realized without the others. The article shows their importance both in the accession procedure as well as after obtaining by a state membership in the organization. When a state decides to become a member of the Council of Europe, it assumes a set of obligations which it should fulfil. Therefore, during the accession procedure, the candidate’s compliance with the membership conditions is assessed. This procedure played a key role in the influence of the Council of Europe on the implementation of democratic standards in the countries of Central and Eastern Europe, when they applied for membership in the Council. On the other hand, after obtaining membership, the control of compliance with the assumed obligations is based on the monitoring procedure of the Parliamentary Assembly and the Committee of Ministers of the Council of Europe. A state which does not respect the standards adopted within the organization challenges its own right to participate in it, as axiology constitutes an important premise of joint action of states within the Council of Europe.