Giuliano Zetti was born in Florence in 1910 and from 1923 attended the Italian State Art Institute in Porta Romana, followed soon after by his younger brother Italo, who was later to become one of the most well-known engraver-xylographers of the 20th century. In 1929-30 he continued his studies attending the advanced course in decorative and mural painting. The art school gave him the opportunity to meet and establish relationships with numerous fellow students who were also later to become acknowledged as talented artists.

In 1931 he obtained his diploma and subsequently was awarded a professorship at the Art Institute of Pistoia. It was in this period that he carried out various works such as the fresco portraying the Miracle of Saint Anthony in the church of the Sacro Cuore in Montemurlo, the restoration of the frescoes in the Chiesa della Fonte in Monsummano, and the tempera painting of the lunette in the former Caffe Doney in Florence. He took part in the 1937 Universal Exposition in Paris, presenting two female portraits. He also participated in the decoration of the windows of the Salone del Transatlantico in Saturnia and collaborated with the Porcinai Tempestini and Baroni Garden Planning and Design Studio, contributing numerous sketches and water colours.

Between 1943 and 1945 he was deported as prisoner of war to the German concentration camps of Harmerstein, Benjaminovo, Sandbostel and Wietzendorf, during which period he produced many paintings depicting the environment and living conditions in the camps. These paintings have been shown at the many expositions held by the National Association of Prisoners of War. In the post-war period he often worked in villas throughout Tuscany adorning them with frescoes and graffiti whilst at the same time continuing his personal painting activity in his studio on Lungarno Corsini. He also carried out numerous works as an interior and garden planner, designing among other things the Garden of The Iris, which was inaugurated in Florence in 1957. In 1971 he received an award at the first National Painting Exhibition in Foggia.

In 1982, in response to much encouragement and public demand he finally presented, at the Fidia Gallery in Rome his first personal public exhibition, followed in 1984 by his exhibition in Santo Domingo. In 2004 some of his works were displayed at the inauguration of the Transtoria museum in Faleria near Viterbo.
He died in in Florence in 1984 at the age of 74.