Parish church in neoclassical style.
It dates back to 1729.
It was erected on the site of two previous churches: the first, dedicated to S. Giovanni, was involved in the destruction of the castle in 1559 while the second was erected in 1578.
Of particular value is the eighteenth-century door.
The church of S. Dionigi dates back to 1729 but previously there were two more ancient ones, one dedicated to S. Giovanni who was involved in the destruction of the castle in 1559 and a subsequent erected in 1578 by the will of Gregory XIII and dedicated to the Virgin Mother of God, of which there is testimony in a plaque on the right of the entrance; the current building has undergone numerous changes especially inside.
It is in neoclassical style, with three naves, it was frescoed in 1905-1906 by the painter Ovidio Fonti and restored in 1988-1989 by the restorer Enrico Baffoni.
The main facade was raised in the 60s, the capitals were made of cement; the eighteenth-century door in inlaid walnut is particularly noteworthy; the two side facades are exposed brick with lime mortar and were restored in 2000.
The main altar in masonry and stucco is elegantly decorated with frames, broken down and heads of angels according to the taste of the time.
On the left side the signature of Domenico Tabacchi and the date of 1833.
The balustrade is in Gassino marble, a nineteenth-century work of Biaggio Sartorelli di Bagnasco, who worked there in 1832; it is the son of the stonemason Domenico Sartorelli and Paolo's nephew.
The same Biaggio will build in 1847 the steps of the Major Altar of the parish of Capriglio and in 1850 will contribute to the construction of the Church of S. Grato di Bagnasco.
Four side altars in stucco are of particular value: the richest is dedicated to the Holy Virgin, the others are dedicated to S. Margherita da Cortona, to St. Antonio da Padova, to the Sacred Heart of Jesus (formerly to St. Sebastiano).
The organ, from the Lombard school, is enclosed in a wooden box leaning against the wall. It was probably built in 1895, it comes from a church in Monza and was installed in Montafia in 1953 by the organist Giovanni Bai.
In 1897 the parish priest Don Giuseppe Raschio placed the canopy there and a few years later, in 1904, he decorated the pulpit.
The papal stone, to the right on entering, has the coat of arms of Gregory XIII concerning the dedication to the Virgin Mother of God and is dated 1578.