The contribution summarizes the first findings of the research into labour strike movement in Czechoslovakia between 1945 and 1948 which has been undertaken as part of the Czech Grant Agency project “Industrial Workers in the Czech Lands between 1938 and 1948”. During the research in the All-Union Archive of the Czech-Moravian Confederation of Trade Unions in Prague, the Archive of Security Services and in other archives, data on 262 strikes were gathered – nearly twice the number of hitherto known strikes in the years 1946–1948 in Czechoslovakia. Based on the analysis of strikes in Czech industry, six stages of the labour strike movement may be found within the observed period. First of them, lasting from May 1945 to June 1946, only brought a minimum number of mostly political strikes which represented the prototypes of various forms of political coercion used by the “left-wing cartel” of the Communist Party of Czechoslovakia and of the Revolutionary Trade Union Movement. After a short break in the summer of 1946, the intensity of political strikes from October 1946 to March 1947 increased again in the context of the so-called battle over seized property and culminated in the well-known Varnsdorf strike. Yet, nearly three-fifths of conflicts at this stage consisted of strikes for social or wage demands which were in many cases comparable by their scope with the political strikes or strikes for a variety of personal or organizational changes. After a further decline in the intensity of strikes in the spring of 1947, then, the period from the beginning of the summer of 1947 to January 1948 was dominated by a wave of spontaneous protest strikes against the introduction of new performance standards and piecework pay. The post-February defensive worker strikes against the lowering of wages and poor supply stopped for a transitional period. However, in the summer of 1948, they broke out in dozens of factories again. The majority of them only lasted for a few hours, with the exception of the three-day strike in Silesian cotton plants in Frýdek which reached beyond the boundary of a single plant and threatened with calling solidarity strikes in heavy industry in the Ostrava region. The State Security (StB) did not yet intervene during their liquidation, but they continuously monitored them and, as soon as the threat of a strike had passed, they did not hesitate to take hard measures against the leading figures.