As much as the means of expression of pop art shaped his paintings until the 1970s, later he created gestural and expressive compositions where the dominant theme is nature. What is objective turns increasingly into what is abstract. In the 1970s and 1980s he gave lectures at the Academy of Fine Arts in Karlsruhe. In 1976 and 1980, his works were presented at the Venice Biennale and documenta 7. At the beginning of the 1980s, Kirkeby turned away from paintings to focus intensely on bronze sculptures. In the 1990s, Kirkeby gave lectures at Städelschule in Frankfurt am Main. In 2008, the Louisiana Museum of Modern Art organised his first retrospective, followed in 2009 by the Tate Modern in London and the Museum Kunstpalast in Düsseldorf.