This paper describes a petrographic guide of Torino, organized as a multimedia CD-ROM. It considers the monuments and historical buildings that are especially interesting or significant as to the stones used and from the historical or artistic point of view. Specific lithologies are described in filig cards which illustrate the geological, petrographical, lithoapplicatory and durability features. The CD-rom also includes a short note on the geological setting of Piedmont stones, a comprehensive bibliography and five geological maps.