Different types of building stones have been macroscopically and petrographically characterized at the ancient city of Sagalassos (SW Turkey). The natural building stones include limestone, conglomerate, breccia, marble, travertine, granite and sand- to siltstone of different qualities. The provenance of most of the building stones may be related to local lithological units, both in the immediate area of the city and on its territory. Also, some stone types were clearly imported from considerable distance. Throughout the history of the city, local beige and pink good quality limestone remained the most important building stone. Both the high quality white limestone from the territory of the city and the marbles imported from a distance of 250 km, represent only a small fraction of the total amount of building stones used. While the use of the white limestone can be considered to form a clear but limited trend from the Trajanic period (98-117 AD) onwards, the import of the marbles must be considered as a rare event. The selection of building stone went hand in hand with the appreciation for structural strength and suitability for carving complex architectural decoration, together with the desire to obtain a polychrome architecture.