Bischofberger abriu sua primeira galeria em 1963 na Pelikanstrasse, em Zurique, então sob o nome de City-Galerie. Em 1965, ele organizou sua primeira exposição de Pop Art na galeria com obras de Roy Lichtenstein , Robert Rauschenberg , Andy Warhol , Tom Wesselmann , Claes Oldenburg e Jasper Johns . Na década de 1970, Bischofberger continuou a exibir a pop art americana junto com os defensores do minimalismo, da arte da terra e da arte conceitual , como Sol Le Witt, Donald Judd ,Dan Flavin , Bruce Nauman , Joseph Kosuth e On Kawara , e representantes do Nouveau Réalisme em Paris, como Yves Klein , Daniel Spoerri e Jean Tinguely . Entre 1982 e 2005, um catálogo em três volumes da obra de Jean Tinguely foi publicado pela esposa de Bischofberger, Christina. Nos anos 80, Bischofberger defendeu figuras-chave dos movimentos neo-expressionistas nascentes, como Miquel Barceló, Jean-Michel Basquiat, Mike Bidlo, George Condo e Francesco Clemente., Enzo Cucchi , Dokoupil, Peter Halley , David Salle e Julian Schnabel .

In 1965, he hosted his first exhibition of Pop Art at the gallery with works by Roy Lichtenstein, Robert Rauschenberg, Andy Warhol, Tom Wesselmann, Claes Oldenburg and Jasper Johns. In the 1970s, Bischofberger continued to showcase American Pop Art along with proponents of Minimalism, Land Art and Conceptual Art, such as Sol Le Witt, Donald Judd, Dan Flavin, Bruce Nauman, Joseph Kosuth and On Kawara, and representatives of Nouveau Réalisme in Paris, such as Yves Klein, Daniel Spoerri and Jean Tinguely. Between 1982 and 2005, a three-volume catalogue raisonné of Jean Tinguely’s oeuvre was published by Bischofberger’s wife Christina. In the 1980s, Bischofberger championed key figures of the nascent Neo-Expressionist movements, such as Miquel Barceló, Jean-Michel Basquiat, Mike Bidlo, George Condo, Francesco Clemente, Enzo Cucchi, Dokoupil, Peter Halley, David Salle and Julian Schnabel.