The MNAC embraces all the arts (sculpture, painting, objets d'art, drawing, engraving, posters, photography and coinage) and has the task of explaining the general history of Catalan art from the Romanesque period to the mid-twentieth century. In the case of the Romanesque and Gothic collections, this discourse is characterized by the Catalan provenance of most of the pieces, although, particularly in the Gothic, comparisons are made with art from other provenances. With regard to the Renaissance and Baroque collections, the works included lead to a more international discourse, with the work of great painters, such as El Greco, Zurbarán, Velázquez, Cranach, Rubens... The MNAC art collections from the end of the nineteenth century and the early decades of the twentieth century are once again mostly made up of the work of Catalan artists, forming a discourse which explains Modernisme, Noucentisme and the Avant-garde, always taking into account all the arts.

A museum is made by its collections, but, as well as conserving them and being responsible for them, it also has to spread knowledge of them, as well as having to make known everything related with research, both from the point of view of art history and museology (conservation, restoration, documentation and diffusion).

As a result of the application of the Museums Law, up to now three Catalan museums have become the Museums Section of the MNAC. Thus, between the Museu Nacional d'Art de Catalunya, the Biblioteca Museu Víctor Balaguer in Vilanova i la Geltrú, the Museu Cau Ferrat in Sitges, and the Museu Comarcal de la Garrotxa in Olot, a link has been established that completes the exhibiting discourses of these centres, with the aim of offering a better understanding of Catalan art.

Moreover, in the context of its characteristic functions with regard to the conservation of the patrimony, taken in its broadest sense, the MNAC performs a series of technical services beyond the strict field of the museum.

With regard to this, the Museum oversees the restoration of monuments and directs operations in painting, sculpture and other artistic techniques, and gives advice to other museum centres on questions referring to safety, museography and preventive conservation.

The MNAC's patrimonial collection, understood in its broadest sense, is made up of both the collections and the material in the Biblioteca del MNAC and the Arxiu General (General Archive).