Roberto De Visiani's activities were primarily aimed at organising the library he received from Bonato  with the obligation of opening it for consultation as the university library. At the same time, the prefect continued to have his own personal library, which at his death was divided between the garden and the Civic Library, to which around 2000 volumes on literary and linguistic subjects were assigned.

Today, De Visiani's former personal volumes are part of the general collection, but there is a manuscript catalogue of this fund. In addition to the classics of botany and medicine, including ancient editions, we also find titles that testify to his interest in fossils.

Browse the catalogue of De Visiani's library in Phaidra.

The library archives contain numerous manuscripts relating to his studies and publications as well as the vast correspondence that demonstrates the network of his connections throughout the scientific world. There are also documents concerning his relations with the Istituto Veneto in Venice and the materials of the Society for the Promotion of Gardening that he founded. In an elegant volume covered in red leather are diplomas and honours from degrees to medals received. In keeping with the spirit of the times, he had collected an album of portraits of botanists that later merged into the Saccardo's Iconoteca dei botanici.