The parish of San Piero in Mercato probably has early medieval origins and it is one of the most ancient nuclei in the territory of Montespertoli. The Museum of Sacred Art has been fitted out inside the parish.

The church's current style undoubtedly dates to the Romanesque period, but many historians and art critics suppose that there was a previous building dating to before the year 1000 and that it was probably demolished in the XI century in the ambit of a new urbanization programme of the area.
During the XIV century, the Parish of San Piero was the seat of a Podestà, the base of an important market and of a homonym League that was born after the union of three parishes, the parish of San Piero in Mercato and the other two parishes of San Pancrazio and of Coeli-Aula. At the end of the XV century, the market that was held near the church was transferred to the centre of Montespertoli and the town hall changed its place, too.
The Parish of San Piero in Mercato has recently been enriched with precious paintings, silverware and wall hangings and it currently houses the Museum of Sacred Art.
The museum, that was born from a synergy among the Region, the Province, the Episcopal curia and the regional board for the cultural heritage, was conceived to gather the works kept in the churches of the area, to preserve them and make them available in one single place for all those who want to admire them.
For instance, all the works coming from the parish of San Piero in Mercato are gathered in the hall: one board by Neri di Bicci, a XVI-century "Madonna col bambino tra i Santi Pietro e Paolo" and a ceramic by the della Robbia representing "San Gerolamo nel deserto".
Moreover, there are also the works coming from the churches of Santa Maria a Mensola, of San Giusto, of San Giorgio and of San Lorenzo a Montalbino, such as the XV-century triptych by Cenni di Francesco, the "Madonna" by Andrea di Giusto and two boards by unknown artists who came from the Sienese and Florentine schools. A board portraying the "Madonna col Bambino" attributed to Lipo di Benivieni or to one of his pupils, and a "gemellion", namely a XIII-century couple of plates used for the washing of the hands, that evidences a French influence in the Valdelsa, represent the patrimony of the church of San Lorenzo a Montegufoni.
The second room is completely dedicated to the churches of Santa Maria a Torre and of San Bartolomeo a Tresanti, with XVII- and XVIII-century works. The works belonging to the parishes of Coeli-Aula and of San Pancrazio are exposed in the third room. The "Madonna col Bambino" by Filippo Lippi, which is considered one of the museum's jewels, comes from the latter churches. A marble font, the Triptych by Bicci di Lorenzo and numerous pieces of silverware further enrich the third room.