The patron saint of Mezzanego is Saint Roch, celebrated on 16 August. The oratory dedicated to him, in the hamlet of Prati di Mezzanego, was once the seat of the Disciplinanti confraternity and was probably built in the second half of the 16th century, later remodelled in the Baroque architectural style during the 19th century: inside, in the apse basin, is preserved a painting depicting the Madonna and Child with saints Anthony and Roch, donated by the Gandolfo family in the second half of the 17th century.
The municipality has four other historic parish churches: Santa Maria Assunta, in the main town in the Castello or Mezzanego Alto area, built in the 17th century; Santa Maria della Neve, in the hamlet of Borgonovo Ligure, which inherited the parish title from the old church of Santa Margherita at Corerallo; San Siro, in the hamlet of San Siro Foce, raised to a parish in 1613 by decree of the Archbishop of Genoa Giulio Spinola; and San Michele Arcangelo, in the hamlet of Vignolo, from the 17th century.
