The National Gallery of modern and contemporary art is located in a monumental palace, built in the neoclassical and Art Nouveau style. It hosts more than 4,000 paintings and sculptures and about 13,000 sketches and prints, which date back to the 1800s and the 1900s. Most of the artists who painted them were Italian (Giacomo Balla, Umberto Boccioni, Alberto Burri, Antonio Canova, Giorgio de Chirico, Lucio Fontana, Amedeo Modigliani, Giacomo Manzù , Vittorio Matteo Corcos and Giorgio Morandi).

The Gallery acquired the works thanks to big national exhibitions, following the Venice Biennale (a major contemporary art exhibition which takes place once every two years) or through donations and legacies. Today the institution is an art gallery of the 19th and 20th centuries, since the 21st century belongs to the MAXXI.

The museum also holds some works by foreign artists, among them Braque, Calder, Cézanne, Degas, Duchamp, Giacometti, Kandinsky, Mondrian, Monet, Jackson Pollock, Rodin, and Van Gogh.

The following institutions are part of the National Gallery: Boncompagni Ludovisi museum of decorative arts, the Hendrik Christian Andersen museum, the Raccoltà Manzù, and the House Museum of Mario Praz.