In May 1945 Gerő became Hungary's minister of trade and transport. In November 1948 he was named assistant general secretary of the Communist Party. A month later he was also appointed finance minister; he continued as trade and transport minister until February 1949. From 1949 to 1952 he served as president of the National Economic Council. During 1952–1956 he was deputy prime minister, and in July 1956 he replaced Mátyás Rákosi as general secretary of the party.
In a radio address the night that the 1956 Hungarian Revolution began, Gerő vehemently refused to negotiate with the insurrectionist reformers. He then asked Moscow to deploy troops to stop the revolution. Two days later, on 25 October 1956, he was relieved of all his posts and fled to Moscow. In 1960 he returned to Hungary on the condition that he be expelled from the Communist Party. As a slavish adherent of Stalinism, Gerő was largely responsible for the outbreak of the 1956 revolution. As president of the National Economic Council, he was the motivating force behind the mass industrialization drive, demanding that Hungary be made "a country of iron and steel." This was an unrealistic goal that unduly taxed Hungarian labor and its industrial resources. Gerő died on 12 March 1980 in Budapest.
Kopasci, Sandor. In the Name of the Working Class: The Inside Story of the Hungarian Revolution. New York: Grove, 1987.; Korvig, Bennet. Communism in Hungary from Kun to Kadar. Stanford, CA: Hoover Institution Press, 1979.