The country's new leaders created a system modeled on Soviet political institutions and practices. Although other political groups were allowed to exist, the only real political force was the Communist party. The legal system and judiciary were subordinated to political ends and opposition to the government was prevented by the secret police. Show trials of party leaders accused of being enemies of the system were held in the 1950's, and many were imprisoned or executed. A centrally planned economy was established: agriculture was collectivized, and almost all private ownership was eliminated. Unified mass organizations dominated by the party replaced the wealth of voluntary associations and interest groups that had existed previously. An effort was made to politicize all areas of life, including education, culture, the arts, science, and leisure time.

In the late 1960s, intellectuals and party leaders, including Slovak Communist Alexander Dubcek, tried to reform the Communist system in what came to be known as the "Prague Spring", or "socialism with a human face". This effort was partly motivated by a desire to improve the performance of the economy and also reflected Slovak demands for greater recognition of their needs in the common state. The reforms, an attempt to create a form of socialism more suited to a developed, European country, included an end to censorship, greater intellectual freedom, and allowing non-Communist groups a greater role in public life. The economy was also to be decentralized. The USSR and its allies feared that the reform would spread to their countries, and Warsaw Pact troops invaded Czechoslovakia on Aug. 21, 1968.

In April 1969, Gustav Husak replaced Dubcek as head of the Communist party. Husak set about eliminating all traces of the reforms. This process, which came to be known as "normalization", ushered in nearly 20 years of political stagnation. Many who had supported reform lost their jobs, and most people lost interest in politics. Certain individuals, however, continued to oppose the regime. Clustered around groups like Charter 77 and VONS (The Committe to Defend the Unjustly Persecuted), they called on the leadership to respect human rights and allow more freedom.