Born in Budapest, Ács entered the Economics Faculty of the Budapest Technical University, but abandoned his studies in 1943. He joined the Hungarian Communist Party in 1945, becoming a district secretary in the same year. He was made head of the Hungarian Workers’ Party (HWP) Central Committee Instructors’ Department in September 1948 and worked in the Organization Department in 1949, before being appointed first secretary of the party in Somogy County in 1950. At the Second Congress of the party in February 1951, he was elected an alternate member of the Central Committee. Ács then completed a course at the Moscow Party Academy and in September 1951, became deputy head of the Central Committee Department of Party and Mass Organizations. At the Central Committee meeting on June 26–7, 1953, he became a full Central Committee member and entered the Secretariat and the Political Committee. He was re-elected to the Secretariat at the Third Congress of HWP in 1954. He then served on the committee set up to implement the resolution on rehabilitating unjustly condemned party members, and from March 1955, on the committee dealing with the rehabilitation of the victims of show trials. From April 1955 to October 1956, he worked as ideological secretary. He was included in an HWP delegation that negotiated in Moscow in 1955. During the October 1956 visit of the Hungarian party and government delegation to Yugoslavia, Ács stood in for HWP First Secretary Ernő Gerő. However, he was dropped from the leading party bodies at the overnight Central Committee meeting on October 23–4, 1956, and on October 30, took refuge at the Polish Embassy. From the autumn of 1958, he served as a department head at the National Bank of Hungary. He obtained the Hungarian Academy of Sciences’ candidacy degree in economics in 1961 and was promoted to deputy head of division at the bank in 1963. Ács studied in the United States on a Ford Scholarship in 1965–6. On his return, he was appointed a deputy head of division at the Ministry of Finance. His fields of study were international finances and the theory of money. On September 14, 1968, Ács committed suicide at his office.