Since the expulsion of the parish priest and his assistants by traditionalist Catholics in 1977, the church has been run by the Society of St. Pius X, which celebrates Traditional Latin Masses there.

On 27 February 1977, traditionalist priest Monsignor François Ducaud-Bourget, who opposed the post-Vatican II Mass, organised a meeting of his followers at the nearby Maison de la Mutualité.

[4] After three months of mediation between the occupants and the Archbishop of Paris, François Marty, Guitton admitted his failure to resolve the issue; the police made no attempt to enforce the expulsion order.

A live stream on YouTube showed the priest and deacons in close contact, without wearing masks, and Holy Communion was given with bare hands.

[11] The construction of the primary facade of the church on Rue Monge, designed by architect Charles Halley, was long unfinished, and was not completed until 1937.

The side doorway along the rue des Bernardins, designed by Charles Le Brun, dates to 1669, and is a particularly good example of the classicism of the period.

[2] The interior of the church is a good example of the Baroque style, lavishly decorated with paintings, medallions and sculpture, dedicated to visually expressing the glory of God.

The chapel in the first traverse displays an early work by Charles Le Brun, called "The Martyrdom of Saint John the Evangelist at the Latin Gate."

"[12] The central feature of the Chapel of Saint-Charles-Boromée is the funeral monument of Charles Le Brun and his wife, Suzanne Butay, made by the sculptor Antoine Coysevox (1640-1720).

[13] The priests of the SSPX at Saint-Nicolas-du-Chardonnet livestream every Mass offered at the church on YouTube, along with Vespers, clergy-led Rosaries, and catechism lessons.