He chose to visit Spain, as Spanish painting was in vogue, particularly the art of Joaquín Sorolla, Ignacio Zuloaga, Camarasa Anglada, and Julio Romero de Torres.

[1] But after visiting Madrid, Toledo, Segovia, Granada, Córdoba, and Seville[3] he settled in Paris where fellow Argentine artists Horacio Butler, Aquiles Badi, Alfredo Bigatti, Xul Solar, Héctor Basaldua, and Lino Enea Spilimbergo were working.

[5][6] Berni continued corresponding with Aragon after leaving France, later recalling, "It is a pity that I have lost, among the many things I have lost, the letters that I received from Aragon all the way from France; if I had them today, I think, they would be magnificent documents; because in that correspondence we discussed topics such as the direct relationship between politics and culture, the responsibilities of the artist and the intellectual society, the problems of culture in colonial countries, the issue of freedom.

He witnessed labor demonstrations and the miserable effects of unemployment[5] and was shocked by the news of a military coup d'état in Buenos Aires (see Infamous Decade).

In 1933 Berni, Siqueiros, Spilimbergo, Juan Carlos Castagnino and Enrique Lázaro created the mural Ejercicio Plástico (Plastic Exercise).

"[9] As one critic noted, "the quality of his work resides in the precise balance that he attained between narrative painting with strong social content and aesthetic originality.

[4][5] In 1941, at the request of the Comisión Nacional de Cultura, Berni traveled to Bolivia, Ecuador, Peru, and Colombia to study pre-Columbian art.

[2] Two years later, he was awarded an Honorary Grand Prix at the Salón Nacional and co-founded a mural workshop with fellow artists Spilimbergo, Juan Carlos Castagnino, Demetrio Urruchúa, and Manuel Colmeiro.

He also painted Negro y blanco (Black and White), Utensilios de cocina sobre un muro celeste (Cookware on a Blue Wall), and El caballito (The Pony).

[2] From his position as Director Of Culture of the Argentine Foreign Relations Ministry (1960) during the government of Arturo Frondizi, art critic and friend Rafael Squirru sent Berni's engravings to the Venice Biennale, where they obtained First Prize in their category.

After Squirru became Director of the Cultural Department of the OAS in 1963, he promoted Berni's work once again organizing prestigious shows for the artist such as the 1966 exhibition at the New Jersey State Museum in Trenton.

[5] As he explained in a 1967 Le Monde interview, "One cold, cloudy night, while passing through the miserable city of Juanito, a radical change in my vision of reality and its interpretation occurred...I had just discovered, in the unpaved streets and on the waste ground, scattered discarded materials, which made up the authentic surroundings of Juanito Laguna – old wood, empty bottles, iron, cardboard boxes, metal sheets etc., which were the materials used for constructing shacks in towns such as this, sunk in poverty.

"[5] Latin American art expert Mari Carmen Ramirez has described the Juanito works as an attempt to "seek out and record the typical living truth of underdeveloped countries and to bear witness to the terrible fruits of neocolonialism, with its resulting poverty and economic backwardness and their effect on populations driven by a fierce desire for progress, jobs, and the inclination to fight.

Art featuring Juanito (and Ramona Montiel, a similar female character) won Berni the Grand Prix for Printmaking at the Venice Biennale in 1962.

[1] After the March 1976 coup, which was like others in Latin America supported by the United States,[11] Berni moved to New York City, where he continued painting, engraving, collating, and exhibiting.

[5][12] In July 2008, thieves disguised as police officers stole fifteen Berni paintings that were being transported from a suburb to the Bellas Artes National Museum.