He briefly served as the minister of treasury and finance in 1944 shortly after the end of the Fascist rule in Italy.

[1] Quintieri worked as a military instructor at the Academy of Turin during his studies in the period of World War I.

[4] Quintieri started a newspaper entitled Il Giornale which folded in 1957 and a weekly La Libertà in June 1944.

[1] In 1944 he and another banker Raffaele Mattioli were assigned by Prime Minister Ivanoe Bonomi as the head of the Italian delegate which visited the USA for the potential economic support.

[6] He also became vice-president of Confindustria in 1949 and then president of the Union of Industrialists which included representations from the six countries of the European Coal and Steel Community.