The patron of Boissano is Saint Mary Magdalene, celebrated on 22 July, in the parish church dedicated to her, in the main hamlet of Piazza, consecrated in 1595 and flanked by an 18th-century bell tower: the interior, frescoed in 1874 by the painter Luigi Sacco, houses a marble tabernacle from 1594, coming from the medieval Benedictine charterhouse of Toirano, and a statue of the saint attributed to the sculptor Gio Batta Maragliano.
According to tradition, the sanctuary of San Pietrino arose when the inhabitants of Toirano contested the right of Boissano's people to go on pilgrimage, on 1 August, to the Benedictine community of San Pietro in Varatella: thus was born the idea of building, on a hill, in a magnificent position, a church dedicated to their ancient protector. The first stone was laid in the Napoleonic era on land belonging to the Molle family, in the Prato district, and the building was completed between 1829 and 1830 thanks to donations from Boissano emigrants in Gibraltar. The town also holds, on the day of Corpus Domini, a historic procession from the parish church to the chapel of Nostra Signora delle Grazie in the Pozzo district, accompanied by a flower carpet, originally of broom blossoms, along the entire route.
