Since 1968 the Art Library holds several special collections that have been enriched with major bequeaths or with acquisitions of private libraries.

Actually there are about 180 special collections with relevance for the study of Portuguese Art and Culture which include private libraries, private archives of Portuguese artists and architects and photograph archives. The Art Library has been developing a plan of cataloguing, preservation and digitization of special collections. For this reason some may be temporarily unavailable. The special collections are searchable on the online catalogue and the ones already digitalized are available on the Internet depending on the copyright terms and conditions.