The collection is especially rich in postwar American and European art. Abstract Expressionism, Pop art, Op art, and art from the 1970s through the end of the 20th century are well represented, including exceptional works from Willem de Kooning, Helen Frankenthaler, Arshile Gorky, Jasper Johns, Franz Kline, Roy Lichtenstein, Marisol, Joan Mitchell, Jackson Pollock, Robert Rauschenberg, Bridget Riley, Mark Rothko, Andy Warhol, and many others. The museum holds the world’s second largest collection of works by the Abstract Expressionist painter Clyfford Still, with 33 paintings (31 of which were gifted by the artist). It is also the world's largest repository of the work of Marisol, who bequeathed her estate, including more than 100 sculptures, to the museum in 2016.
The Albright-Knox continues to add to this collection, and seeks to represent the most important voices in contemporary art of the 21st century. In recent years, the museum has acquired major works by artists such as Matthew Barney, Mark Bradford, Tara Donovan, Harun Farocki, Felix Gonzalez-Torres, Theaster Gates, Rodney Graham, Subodh Gupta, Mona Hatoum, Sopheap Pich, Jaume Plensa, Ursula von Rydingsvard, Cindy Sherman, Hank Willis Thomas, Kara Walker, Jeff Wall, Rachel Whiteread, and many others. These additions to the collection ensure that future generations will continue to discover the incredible diversity of international modern and contemporary art during visits to the Albright-Knox.