Tradition holds that this church shelters the relics of the titular Saint, leading it to become the center for her veneration and for prayers for her miracles.

The stucco decoration of the apse was completed by Giacomo Serpotta, and the frescoes of the cupola were added in the 18th century by Sebastiano Lo Monaco.

In the 16th century, a polychrome wooden statue of Saint Agrippina was placed on a marble pedestal in the chapel on the right side of the church.

From the 17th century, in the dome of the church, there are four hexagonal columns that are covered in an embossed silver leaf.

Numerous stuccoes depicting scenes from the Old Testament adorn the ceiling, and to the right there is a precious crib made from wood.