The Belvedere archivists have been engaged in research on provenance since 1998. The most renowned are the Bloch-Bauer and Mahler-Werfel Collections, but they are by no means the only cases of artworks that were confiscated from Jewish ownership and landed in the museum inventories.

Since 1999, the Belvedere has submitted 72 provenance dossiers before the art restitution advisory committee of the Ministry of Education, involving a total of 138 pictures and sculptures. The range covers a Gothic panel by the Master of the Legend of St Vitus, major works of nineteenth-century Austrian and German painting by Waldmüller, Romako and Feuerbach, and Viennese art of the fin de siècle by Klimt and Schiele ( restitutions since 1999).

However, the provenance research division of the Belvedere investigates on principle all works of art acquired by the museum since March 1938 and created prior to 1938. This inventory amounting to around 5000 paintings, sculptures and graphics was transferred to an in-house database. From now on, this enables researchers to continue archival work in relation to the objects and to classify the works under investigation according to the categories: "unobjectionable", "objectionable" and "open" (details on provenance database).

An end to the provenance research in not yet in sight.