The Czechoslovak National Socialist Party, which changed its name several times over the years and whose legacy is currently claimed by the Czech National Social Party as a successor organization, is one of the oldest traditional Czech political parties. It was established in 1897 in the period of political differentiation of Czech society with the ambition of becoming an association of Czech workers, the organization of which until then had been the focus of the international Social Democratic Party. Eventually, it profiled itself as the party of the lower middle classes, with a nationalistically formulated programme of defending the ideas of democracy, social equality and justice that was aligned with the vision of creating a reformist Czech national socialism. By tradition, it was opposed to Marxism, communism and any kind of totalitarianism, and, after 1918, participated in the building of a democratic Czechoslovak Republic. It defended these policy postulates even after the end of the Second World War, when, in a heavily reduced, centre-left party-political system identified with the concept of the National Front, it profiled itself as the most consistent opponent of the Communist Party of Czechoslovakia (KSČ). While the Communist policy aimed at a complete takeover of power with the objective of the revolutionary transformation of Czech and Slovak society and the building of socialism and communism, the National Socialists unequivocally rejected this concept and aimed at a vision of a national, democratic and socially just state. The clash of these contradictory ideas about the future, which was not specific only to Czechoslovakia, but was related to the formation of the bipolar order of the world and Europe after the Second World War, and the fact that Czechoslovakia found itself in the Soviet sphere of influence, was reflected in the emergence and resolution of the government crisis of Gottwald’s cabinet in February 1948. The KSČ used this case for a coup d’état. It established the dictatorship of the proletariat in Czechoslovakia, liquidated the democratic political system and replaced it with a totalitarian one, and in line with Moscow’s intentions, it began a revolutionary transformation of society with the aim of building socialism. The February Communist coup also had a major impact on political parties, particularly the Czechoslovak National Socialist Party. The Communists, with the help of turncoats and careerists covered by Communist State Security, dismantled that party and began to actually build a new political party from its ruins under the name of the Czechoslovak Socialist Party. In terms of its policy statement, the party identified itself with the visions of the Communists, who made it a shadow organization collaborating with the regime until 1989. This study reflects the circumstances behind the formation of the Czechoslovak Socialist Party in 1948, with a focus on the formation of the party leadership and party elite. People who mostly cooperated with the Communists before February 1948, along with individuals secretly authorized by the KSČ and the security structures to work among the National Socialists for the purpose of intelligence and decomposition activities, established themselves as the leaders of the organization at central level.