This study deals with the structure and changes in Czechoslovak diplomacy at the time of the Communist coup d'etat and shortly thereafter. The Communist Party of Czechoslovakia to which only a small minority of civil servants declared their allegiance prior to February 1948, succeeded in gaining control of the Ministry without any difficulties as early as the very beginning of the putsch. However, a number of Czechoslovak Ambassadors in Western countries, among others those in the USA, France, Canada and the Latin American countries stood against the new power. The attempt of the permanent delegate at the UN, Jan Papanek to persuade the UN Security Council to consider the international aspects of the putsch was the most significant contribution. Even though he was immediately denounced by the new Communist Government, he helped to raise an awareness in the West of the real circumstances of the coup d'etat.