Instituted in 1941, it became a State Archive in 1963. Its material comes from various sources, among them the Municipal Historic Archives and those of the institutions and charity organisations of the city and the surrounding countryside that were collected at the Forteguerriana Library by Quinto Santoli starting in 1927. The Municipal Historic Archives contain, in addition to the official papers of the Commune, those of the peripheral organs of the Tuscan State. Although the documentation begins with the 11th century, it is fragmentary up through the 13th century. The papers from the archives of religious and private bodies are the most important. Especially interesting are the documents from the Central Office for the Embankments of the Ombrone River and its Tributaries (1820-1843) and those of the Office of Works and Impositions on Water Courses, which later became the Hydraulic Consortiums of the Pistoia Territory.

Particularly important, as regards the history of medicine, is the documentation on the Ceppo Hospital and the San Gregorio Orphanage, divided into various repertories (Hospital of Ceppo; Hospital of San Gregorio; Rectory of the Humiliati; Monastery "delle Grazie", or "del Letto"; Abbey of San Bartolomeo the Apostle, known as the Roccettini; Monastery of Ripalta; Associated Hospitals) which contain documents from the 14th to the 20th century.

In 1959 the Pescia State Archive Section was instituted. Noteworthy among the various documents are the historical archives of the Hospital of Santi Cosma e Damiano which include, in addition to the records of the institution itself, the papers of the guilds and religious companies in the Diocese of Pescia, suppressed by Grand Duke Peter Leopold in 1785.