The Chapel of the Nativity, restored between 1750 and 1751, sees the grandiose central cave composed of blocks of karst rock in which the almost life-sized polychrome marble statues of St. Joseph and the Virgin Mary adoring the Child Jesus are placed , as well as, five angels. Above the cave, two other angels with cartouche announce the good news and together with other characters, including the Magi, confirm by animating it the traditional representation of the event of the Nativity.
On the side walls there are frescoes of life scenes with the aim of creating continuity in the facts represented. Under the vault we have a frescoed sky, in which the comet star is represented among a flutter of cheering angels.
In 1569 a report was made by the then Bishop of Polignano, on the occasion of his sacred visit to Putignano, which confirmed the existence in the main church of a nativity scene without the two large statues, which confirms that the statues of San Giuseppe and of the Virgin are from the same period of the arrangement of the Chapel, which took place at the hands of the talented Neapolitan master named Gennaro, who, as reported in the book of the "Notamento dei Sacerdoti", arranged for the displacement of the Nativity from the Chapel of San Giuseppe, present on the left side, in this larger one, already dedicated to San Gregorio Magno. The same master at the same time arranged for the arrangement of the cave and to sculpt the missing statues, according to the artistic tradition of the sixteenth-century Apulian nativity scenes, of which Stefano da Putignano was the proponent.
The statue of St. Joseph, carved in relief on a hollow slab on the back, due to obvious discordant characteristics cannot be attributed to Stefano, lacking the characterizing aspects of his style such as the solemn architectural composure of the figure and the basic way of representing the clothes. The hat dropped on the shoulders of the kneeling Saint and the approximate calligraphic engraving of the folds of the tunic and of the mantle confirm this.
The statue of the Virgin stands out for an entirely eighteenth-century search for grace in the modeling and in the elegant composing or outlining the folds of the blue mantle, even if it is somewhat vague in the not very expressive features of the vow.
In the frescoed parts depicting a vast and delightful countryside, among the pastoral scenes it is easy to identify: the announcement to the shepherds, the bagpipers, the return from work in the fields, a woman accompanying her son.