The village still offers some traces of its medieval structures, including an arched stone door. The town is mentioned in a document of 730 where Warnefred, Lombard Steward of Siena, made a donation to the abbey of S. Eugenio. In the eleventh century it belonged to the Ardengheschi family and in 1203, in its church (San Biagio), the conditions of an agreement between this family and the City of Siena were established. In 1247 San Biagio in Filetta was one of the communities belonging to the state of Siena. In 1262 Siena imposed Filetta to dig, at his own expenses, a well of water, 'the well must have a good bucket chain and a good coverage that allows its closing at night.' In August 1313 the Emperor Henry VII of Luxembourg camped with his army in Filetta, in order to cure his disease in the thermal waters of Doccio, not far from the village, on the left bank of the river Merse. The remains of the bath, in operation until the mid '900, are still visible.