The archival approach to the study of the history of psychiatry in Italy was of great importance, having allowed an early interest in the recovery of documentary materials at risk of dispersion by the application of the ‘Basaglia law’. In the article, after a historiographical assessment on the subject of conservation of archives of psychiatric institutions, the case of the Arezzo neuropsychiatric hospital is addressed, outlining its institutional dimension from the first studies at the end of the XIX century up to its full efficiency during the XX century. Having defined the bureaucratic practices adopted in the institute and the methods of production, conservation and transmission of documentary material, the sources are highlighted which allow us to deepen the study of the painting atelier set up there, both by analyzing the documentary typologies present today in the historical archive of the hospital, and by extending the research to what can be recovered from private entities.