The church was later sold to the diocese of Rome, who transformed it into the parish: it was established June 22, 1936 with the decree of the Cardinal Vicar Francesco Marchetti Selvaggiani Dominici Gregis.

The church is home to the cardinal's title of "Our Lady of Guadalupe a Monte Mario", founded by Pope Paul VI April 29, 1969.

On the high altar of the church is placed the image of Our Lady of Guadalupe, the work of a Mexican priest donated to Pope Leo XIII in 1880 and then donated in 1929 by Pius XI to Mexican nuns.

Pius XII in 1955 proclaimed Our Lady of Guadalupe "Queen of labor": at that time the image was placed a crown, made by the engraver Guido Veroi.

The presbytery, of exquisite workmanship, is an altar made of perforated white marble.