His art is characterized by social and political commentary,[1] and as a member of the Italian Communist Party (PCI) he became its senator for two legislatures, from 1976 to 1983, during Enrico Berlinguer's secretariat.

Guttuso also designed for the theatre (including sets and costumes for Histoire du Soldat, Rome, 1940) and did illustrations for books.

Guttuso lived close to a house amongst the Valguarnera villas and Palagonia, which he would soon represent in paintings inspired by the cliffs of Aspra.

In Palermo and Bagheria Guttuso observed the dereliction of 18th-century villas previously belonging to the nobility, abandoned to decay as a consequence of political infighting within the municipal chambers.

[4] In 1931 two of his paintings were accepted by the jury of the Quadriennale di Roma and were included in a collective exhibition of six Sicilian painters at the Galleria del Milione, Milan, which aroused great interest among the Milanese artistic milieu.

[5] Back in Palermo Guttuso opened a studio in Pisani street and together with painter Lia Pasqualino and sculptors Barbera and Nino Franchina formed the Gruppo dei Quattro (The Group of Four).

He lived close to significant artists of the time: Mario Mafai, Corrado Cagli, Antonello Trombadori, also keeping in contact with the group from Milan of Giacomo Manzù and Aligi Sassu.

Here he developed his "social" art, with his political attitudes evident in paintings such as Fucilazione in Campagna (1938) and Escape from Etna, the former dedicated to the poet Federico García Lorca, who had been shot by Franco's supporters during the Spanish Civil War.

Socio-political themes dominated Guttuso's work during this time, depicting the day-to-day lives of peasants and blue-collar workers.

In the following years Guttuso painted Contadino che zappa (1947) and Contadini di Sicilia (ten drawings published in Rome in 1951), in which his pictorial language became clear and free of all superfluous elements.

Guttuso wrote that these were preparatory sketches for his 1949 painting Occupazione delle terre incolte in Sicilia ("Occupation of uncultivated lands of Sicily"), exhibited at the Venice Biennale in 1950.

[9] In 1950 Guttuso joined the project of the Verzocchi collection (in the civic Pinacoteca of Forlì), sending a self-portrait, and the works "Sicilian labourer", "Bagheria on the Gulf of Palermo" and "Battle of the Bridge of the Admiral".

Guttuso also painted a series from life about the fight of the peasants for occupied lands, the sulfur miners, or glimpses of landscape between cactus and prickly pears, as well as portraits of men from contemporary culture such as Nino Garajo and Bruno Caruso.

In addition to Guttuso himself, Marx, Engels, Trotsky, Elio Vittorini, Angela Davis, Stalin, Lenin, Jean-Paul Sartre, Simone de Beauvoir, Pier Paolo Pasolini and others are also depicted.

After speculation about who would be the rightful owner of the painter's work, two prosecutors were appointed to settle the dispute between Guttuso's nephew, his adopted son Fabio Carapezza Guttuso (who had been adopted only four months before Renato's death, was 32 years old and was already recognized as the son of Marcello Carapezza), his longtime lady friend Marta Marzotto, Rome's Museum of Modern Art, along with an assortment of other slighted acquaintances to high-ranking government and church officials.