The Prato State Archives Section, instituted in 1957, occupies premises on the first floor of Palazzo Datini, a residence purchased and entirely remodelled in the last decades of the 14th century by Francesco di Marco Datini. It contains the remarkably rich "Datini Archives", now also fully digitized and available on-line, with the business and private correspondence of the famous Prato merchant and banker from 1382 to 1410. Some of the letters have samples of woollen cloth attached to them. Particularly interesting are the Municipal Historical Archives and those of the Prato Misericordia e Dolce Hospital. The notarial records, those of the religious corporations and the Diplomatic Archive are kept in the State Archive of Florence.

Other interesting documents are those pertinent to the Accademia degli Infecondi, literally the Unfruitful ones, founded around 1712 as a theatrical and literary academy. In the early years of the 19th century the academy assumed a new orientation, attempting to conjoin science and literature, and continued in this direction until its activity came to an end in 1841. Accordingly, it engaged in discussions on Italian history and literature, but also on hydraulics, vaccination, the popular teaching of geometry and of mechanics applied to the arts and trades, as well as the industry and economy of Prato.