The Great Gallery of Palazzo Giustiniani, now known as Zuccari Hall having been named after the artist who painted the fresco on the ceiling, Federico Zuccari (1539-1609), is the only room left untouched during the subsequent renovation works in the building.

It is entirely decorated with frescoes: the ceiling depicts five episodes from the stories of Solomon (Solomon anointed king, the construction of the Temple, Solomon's judgement, the children forced to stab their father's corpse and, in the centre, Solomon meeting the Queen of Sheba) and the four virtues attributed to him ("Religion", "Industriousness", "Watchfulness" and "Eloquence"). Near the corners of the ceiling there are some small landscapes in round frames. The walls were graced with female figures representing the virtues, but the only whole-length figure left today is "Temperance", although fragments of the others may also be seen. All decorations are arranged on a surface painted with grotesques, creating a magnificent overall effect, which is further enhanced by 17^th-century tapestries.

Uncertainty about the authorship of some of the paintings still remains. As to the important decoration cycle dating back to 1586-87, before the building became a Giustiniani family's property, recent studies have confirmed that they are to be ascribed to Antonio Tempesta (1555-1630) and Pietro Paolo Bonzi (1576-1636).