The post-war years saw a return to intense cultural activity in Rome. The exhibitions staged by the Galleria Nazionale d'Arte Moderna, the many initiatives by private galleries, the formation of groups based around artistic trends, the clashes between devotees of abstract and figurative art - all of these elements contributed to creating the environment of fervent activity which made the Rome of the 1950s an international city and a destination for foreign artists.
The first Quadriennale after the war was organized in the Galleria Nazionale d'Arte Moderna, under the direction of the administrator, sculptor Francesco Coccia, since the Palazzo delle Esposizioni had been rendered virtually unusable by the various occupations.
After the Exhibition of the Reconstruction, held by the Ministry for Public Works in 1950, and the reassembly of the Ente Quadriennale (Quadrennial Authority) with Fortunato Bellonzi as general secretary, the restoration of the building began. The work of renovating the rooms and mounting the exhibition was assigned to engineer Giacomo Maccagno, an employee of Rome City Council, and architect Adolfo Bobbio, while Mario Bellina was responsible for the work on the bar and the reception rooms. The stucco and plaster work was renewed, the floors were renovated, the central rotonda was rescued, the building systems were renovated, the lamps were shaded with curtains, and the exhibition space was increased with the use of many mobile partitions, later used for other exhibitions. The Sixth Quadrennial was then inaugurated on 18 December 1951; there were several retrospectives, including one on Modigliani curated by Jean Cassou.
Two very important exhibitions also took place during the 1950s in the Palazzo delle Esposizioni: the exhibition on Seventeenth Century Europe held by the Council of Europe (November 1956 - February 1957), an exhibition that would not be possible today because of its size and the importance of the loans made to it by museums from all over the world; and the exhibition on Seventeenth Century Rome in 1959, which gathered together 2,600 works of art, including 600 paintings, as well as sculptures, gold artefacts, furniture and a great variety of other objects testifying to the cultural life of the period.
The exhibition on Mexican art from ancient times to the present day (October 1962 - January 1963) was another remarkable event: it provided a vast record ranging from the Pre-Christopher Columbus culture to Latin American Baroque, and continuing up to the works of contemporary artists housed on the upper floor of the building, including Rivera, Siqueiros, Orozco, Rufino Tamayo, and Frida Kahlo, as well as a collection of handcrafted artefacts. These exhibitions concluded an excellent cycle of exhibition activity which did not continue into the 1960s, when the activities of the Palazzo delle Esposizioni were reduced to a collection of pointless, very mediocre initiatives, with the exception of the Quadriennali (Quadrennial Exhibitions).
The Seventh, Eighth and Ninth Quadriennale took place during the ‘50s and ‘60s (1955, 1959, and 1965). The controversy between the abstractionists and the realists lay at the heart of the Seventh Quadrennial, with strongly contrasting critical positions. At the centre of the exhibition, an important nucleus of paintings and sculptures reconstructed the panorama of Italian art from 1910 to 1930. There were numerous retrospectives, including one on Savinio curated by Giorgio de Chirico, one dedicated to Atanasio Soldati curated by Nello Ponente as well as various others. This exhibition, which brought together about 3000 works of art including sculptures, paintings and works in black and white, was definitely considered by most people to be the best exhibition of the post-war years.
The Seventh Quadrennale took place from December 1959 to April 1960, mounted by architects Melis and Clerici. The central feature was an exhibition dedicated to the youthful Rome School from 1930 to 1945, curated by Giorgio Castelfranco and Emilio Lavagnino, while the commission responsible for the invitations was strongly contested by a large group of artists linked principally to abstract and informal exploration (including Vedova, Turcato, Leoncillo, Burri, Dorazio, Afro, Mastroianni etc.). The retrospectives dedicated to Balla, curated by Enzo Francia, Licini, curated by Giuseppe Marchiori, Prampolini, curated by Vittorio Orazi, and Spazzapan, curated by Fortunato Bellonzi and Renzo Romero, helped to restore some calm to the heated atmosphere.
The Ninth Quadriennale was inaugurated in the month of October 1965 and was set up by Mario Melis. There were many retrospective exhibitions for artists such as Morandi, Mafai, Sironi, Casorati, Donghi, Fortunato Depero, Romagnoni and Tancredi. The exhibition also included the latest trends in artistic research, ranging from the new situation in Rome, represented by Angeli, Festa, Ceroli, to kinetic art. Among the award-winners were Mirko, Alberto Viani, Turcato and Perilli.