The Vatican Museums Photo Library preserves the legacy of the historic Photographic Archive, established in the 1920s as an integral part of the "Sculpture Museum”. In the 1930s the Archive was subsequently separated and moved to the third floor of the new building designed by Luca Beltrami for the Pinacoteca, where it still remains today. In 2010, Antonio Paolucci reorganised it, focusing its activities on the care, protection, study and dissemination of the historical photographic collection, made up principally of black and white photographs – separating it from the current colour archive, digital documentation and the legal-administrative aspects related to the provision of images to the public, entrusted to the Images and Copyrights Office.

The collection, which initially consisted mainly of documentation of the works in the Museums, the displays and the wall paintings in the palaces, commissioned by the Directorate from professional photographers for the compilation of inventories, for study and for specialist publications, expanded considerably with the acquisition of the collection of the photographer Romualdo Moscioni (1849–1925). The addition of the Moscioni collection between 1931 and 1932, with over 15,000 glass plate negatives, significantly increased the patrimony and variety of subjects and led to the systematic printing of the negatives, entrusted to photographer Arturo Faccioli.
Other notable collections include those of Anderson, Faraglia, Felici and Brogi. The photographic campaigns carried out by Domenico Anderson between 1932 and 1934, dedicated to the Last Judgement and the Pauline Chapel, are particularly significant.
Likewise, the photographs of Rome occupy a central role, with archaeological views, churches, the countryside and surroundings, but also museums, villas, palaces, streets, monuments, forums, fountains, squares and cemeteries. Italy is also amply represented through its most significant monuments, urban views and landscapes. Of particular note is Romualdo Moscioni's Apulia Monumentale campaign, carried out between 1891 and 1892 on behalf of the then Ministry of Education, dedicated to the Romanesque monuments of Puglia, Campania and Basilicata. There is also photographic documentation relating to works and artefacts from Italian and foreign private collections, as well as the VCS Events Collection, which includes a substantial record of events linked to the activities of the Museums, in addition to the Pontiffs and Exhibitions sections.

Also worthy of note is the Ferper Fund, named after the physician Ferdinando Perez, author of photographs of the principal paintings preserved in Italian and European museums, taken using grazing light and an instrument of his own invention, the pinacoscope.
The Busiri Vici Collection, from the architect and art historian Andrea Busiri Vici (1903-1989), features among the more recent acquisitions: the subjects relate primarily to painting from the fourteenth to the nineteenth century, the history of collecting and art history, as well as the history of landscape and architecture.
Today, the historical photographic heritage entrusted to the Photo Library consists of approximately 55,000 glass plates, approximately 350,000 black and white film negatives and 400,000 positives.