The 20th-century paintings, sculptures and drawings range from Fauvism to Contemporary Art, and are shown in chronological and thematical displays.

The neo-classical works by Jacques-Louis David rub shoulders with the pieces by his pupil, Jean-Auguste-Dominique Ingres. The Romantics are represented by Eugène Delacroix, Théodore Géricault, Antoine Wiertz and Louis Gallait. Realism is showcased via works of Gustave Courbet, and the site also holds Impressionist paintings by Alfred Sisley and Émile Claus.

Pointillists Theo Van Rysselberghe and Georges Seurat are set alongside the Nabis, who lay the groundwork of non-objective art. James Ensor is represented by pieces spanning all stages of his artistic career. Belgian symbolist Fernand Khnopff, early 20th-century Rik Wouters (a key figure of Fauvism), Expressionist works by Constant Permeke and Gustave De Smet, and avant-garde pieces of the late 1920s, are featured along with the creations of René Magritte. The museum holds one of the largest public collections of Magritte's work, as well as the Conceptual Art of Marcel Broodthaers, and contemporary trends showcased by Wim Delvoye and Panamarenko.