Giovanni Battista Derchi attended the courses of the Ligustica Academy of Genoa with great profit, later devoting himself to the decoration of Genoese cafes and theaters as an assistant to Fantoni. For health reasons he went to Bergamo, where he collaborated with the painter Taragni on various decoration works (from June to September 1902). In 1903 he collaborated with Fantoni on the decoration of the vaults of the arcades of Via XX Settembre in Genoa; and in the same year he participated in the exhibition of the Promoting Society of Fine Arts. In 1911 he was commissioned to remove the fresco "The abduction of Elena", by Luca Cambiaso, in the Villa Scassi in Sampierdarena; it was on this occasion that Giovanni Battista Derchi began to perform a series of works (oils, watercolors, drawings) which highlighted the most characteristic corners of the Villa itself. For this reason, he was nicknamed the painter of Villa Scassi. His palette sees predominantly pinks, greens, reds to create a suffused tonalism, still linked to the atmosphere of the Gray School. Numerous retrospective exhibitions, we mention the first of 1957 in Genoa at the Genoa Gallery (68 works in total including paintings and drawings). Works by him are kept at the Picture Gallery of the Civil Hospitals of Genoa Sampierdarena.