These are the proceedings of the international conference “Formation and Evolution of Galaxy Disks” organized by the Specola Vaticana (the Vatican Observatory). The meeting hosted 198 participants from 26 countries. The program consisted of 61 talks and about 130 poster papers. In 2000 the Vatican Observatory organized a conference on Galaxy Disks and Disk Galaxies, the proceedings of which were published in ASP Conference Series Vol. 230. Since that time, a great amount of work has been done in this very active field. October 2007 was deemed an appropriate time to hold another similar conference where outstanding senior and junior astronomers in this field could air new results. The conference was focused on the formation and evolution of galaxy disks and covered the following topics: (1) properties of nearby galaxy disks; (2) interstellar medium, star formation, and chemical evolution; (3) disk edges, outskirts, and environment; (4) accretion onto disks, interactions, and mergers; (5) secular evolution of disks and bar/spiral driven evolution of galaxies; (6) evolution of disk structural properties; and (7) disk formation in a hierarchical universe. This books is of interest for researchers in extragalactic astronomy. It presents an overview of the relevant results and the progress made in the field in the last seven years.