On the façade of Santa Maria della Scala are set four ancient inscriptions that recount a significant part of the centuries-old Sienese institution.
The first is positioned at the mouth of via dei Fusari, above an arch, today filled in, on the ground floor of the Palazzo del Rettore, the institutional figure who led the institution from its origins. The plaque consists of a rectangular marble slab in good condition, which was probably placed immediately after the construction of the wall, marking the completion of the palace's building works, dating to 1290. Below the epigraph the heraldic emblem of the city of Siena was placed, the 'Balzana', a shield divided horizontally with white (silver) in the upper part and black in the lower.
On the filled-in arch of the Palazzo del Rettore, beneath the previous epigraph, there is a second one, also in marble but without a frame, bearing at the top the ladder, symbol of the hospital, in the center the inscription «Limosine di grano A. D. MDLXXXIIII» and, below, the coat of arms of the Saracini family.
The third inscription is affixed to the tympanum of the last arch of the hospital front facing via del Capitano. It, well preserved and formed by an almost square marble slab, without a frame or decorative elements, recalls that in 1298 the hospital opened the large building site to construct the part to the left of the church intended as a home for the gettatelli and the wet nurses, that is for the reception of abandoned children, the so-called "gettatelli", who were already numbering over three hundred.
The last of the four ancient epigraphs present on the façade of Santa Maria della Scala is not legible from the ground, being located at the level of the first floor of the complex's left section. The plaque, where the cross and a large ladder, symbols of the institution, are carved, recalls an enlargement of the building that took place in 1338, under the rectorship of Giovanni di Tese Tolomei, intended as a hospital for women.