Born in Udine in 1912. Trained in Venice and Florence in 1928, just sixteen, he exhibited together with his brothers Dino and Mirko at the first and only Exhibition of the Friulian Avant-garde School. In 1930 he moved to Rome, where he came into contact with the protagonists of the Roman School: Scipione, Mario Mafai and Cagli.
From 1931 he began to participate in various trade union exhibitions and in 1933 he exhibited at the Galleria del Milione in Milan.
In Rome he joins the group of artists (Capogrossi, Cavalli, Fazzini, Guttuso, Leoncillo, Pirandello) which revolves around the Galleria della Cometa by Libero and Corrado Cagli. In 1935 he exhibited at the Rome Quadriennale, in 1936 at the Venice Biennale; in 1937 he is in Paris, where he works with Cagli, works on decorations for the International Exhibition and approaches Impressionist and Cubist painting.
In the following years he is engaged in numerous fresco works.
He also participates in the Quadriennale of Rome (1939, 1948), in some of themeditions of the Bergamo Prize and the Venice Biennale (1940).
In 1949, after having exhibited at the New York MoMA at the XXth Century Italian Art exhibition, he stayed for some time in America, approaching the production of the American Action Painting artists, Kline and De Kooning in particular, whose poetics he reworked. He begins the twenty-year collaboration with the Catherine Viviano Gallery.
Returning to Rome in 1951, he won first prize at the San Paolo Biennial in Brazil.
Between 1952 and 1954 he was part of the Group of Eight which brought together many artists of the New Front of the Arts (Birolli, Morlotti, Turcato, Santomaso, Vedova). Together with the whole group, sponsored by Lionello Venturi, Afro exhibits at the XXVI and XXVII Venice Biennale (1952 and 1954), in Hanover, Cologne and Berlin.
In 1955 he exhibited at the first Documenta in Kassel, at the Quadrennial in Rome and at The New Decade: 22 European Painters and Sculptors exhibition at the MoMA in New York (later in Minneapolis, Los Angeles and San Francisco).
In 1956 he won the first prize as best Italian artist at the Venice Biennale, an edition in which he participates with a personal room. In 1957 he returned to America and in 1958 he took part, together with Appel, Arp, Calder, Matta, Miro, Moore, Picasso and Tamayo, in the decoration of the new headquarters of the UNESCO building in Paris by painting The Garden of Hope. In the following years he is involved in numerous international exhibitions.
After the death of his brother Mirko, which took place in 1969, Afro suffers various health problems. The seventies are characterized by the intensification of the graphic work and a thinning out of the pictorial and exhibition activity. In 1973 he took part in the 10th Rome Quadriennale as part of the exhibition Situation of non-figurative art.
He died in Zurich in 1976.