[citation needed] In 1997, the museum opened the Galerie der Gegenwart building, an extension of 5,600 square metres (60,000 sq ft) that was designed by Cologne architect Oswald Mathias Ungers and that is dedicated to the Kunsthalle's contemporary art collections.

The Old Masters Collection shows works by Bartel Beham, Bernardo Bellotto, Lucas Cranach the Younger, Master Francke, Francisco José de Goya y Lucientes, Johann Georg Hinz, Jan Massys, Giambattista Pittoni, Rembrandt Harmensz van Rijn, Peter Paul Rubens, Jacob Isaacksz van Ruisdael and Giovanni Battista Tiepolo, among others.

The Gallery of 19th-century Art shows work by Carl Blechen, Arnold Böcklin, Gustave Courbet, Edgar Degas, Anselm Feuerbach, Caspar David Friedrich, Jean-Léon Gérôme, Wilhelm Leibl, Max Liebermann, Édouard Manet, Adolph Menzel, Claude Monet, Auguste Rodin and Philipp Otto Runge, among others.

The Gallery of Contemporary Art shows works by Joseph Beuys, Tracey Emin, David Hockney, Rebecca Horn, Ilya Kabakov, On Kawara, Yves Klein, Kitty Kraus, Robert Morris, Hermann Nitsch, George Segal, Richard Serra, Franz Erhard Walther, and Andy Warhol, among others.

In December 2023, the museum received public criticism for its response to a restitution claim by the family of Holocaust victim Robert Graetz concerning Paula Modersohn-Becker's painting Girl's Head.

The museum director Alexander Klar rejected the claim stating, "It is simply not clear whether this work is the one that hung in the Robert Graetz collection.