Above the facing door is the Monument to Pius X, squeezed into a rather small niche. The Pope is shown, entirely in white marble, with his arms outstretched. The conception and execution of the later metal bas-reliefs are elegant, but they are not in keeping with the statue. They illustrate the major works of this canonized Pope, such as the acceptance of Church doctrine by the learned men, against excessive modernity; the consecration of 15 French bishops, the reorganization of the Curia, the reconstitution of Canon Law and Gregorian Chant, to support the struggle against secularism; the founding of the Bible Institute and the reorganization of the Vatican Pinacoteca.

The architect of this cenotaph, inaugurated in 1923, was Florestano Di Fausto; the sculptures are the work of Pier Enrico Astorri.