Gatteri was described as a child prodigy; by the age of 11 he impressed members of the Minerva Society in Venice with his ability to improvise drawings of episodes from antiquity.

[1] [Notes 1] Gatteri's teachers encouraged him to follow the Romantic style of painting while respecting the Venetian school's tradition of warm color.

In a magnificent villa on the Via Ginnastica in Trieste he painted the ceiling of one of the rooms with a fresco 5 metres (16 ft) square depicting a youthful Emperor Franz Joseph I of Austria and the Empress Elizabeth on horseback surrounded by heraldic symbols and lesser personages.

The Revoltella Museum in Trieste contains many of his masterworks, including: The Feast of Mary, Arrival of the Queen of Cyprus in Venice (1864), Entertainment given by Cardinal Riario to the Duchess of Ferrara (1872), Cesare Borgia leaving the Vatican (1877) and Minerva awarded the Arts and the Virtues (1884), thought to be his last work.

[7] Gatteri's works, whether in oils or on paper, were always dramatic compositions, decorated with rich period costumes, brightly colored or bejeweled or shining armor.

[1] force and truth of his outlines, the correct proportion of the figures, the spirit of the attitudes, the eloquence of expression in the faces, the fidelity of the costume, the happy arrangement of all the accessories, the grace and beauty of the groups and episodes, and the wonderful harmony of the work as a whole.