From his debut in 1958 onwards, Belgian artist Jef Geys (b. 1939) worked with photography. This makes him an absolute pioneer within the Belgian art world—immediately followed by Jacques Charlier and Marcel Broodthaers, who from their debut in the early 1960s also made photo-based art. Throughout Geys’s multimedia practice photography takes a prominent place: not only in the number of works that involve photographs but also in the establishment of his archive, which is a fundamental component of his work. In addition, what makes Jef Geys an interesting case is that his idiosyncratic oeuvre spans the whole period in which photography became an autonomous medium within the domain of contemporary art in Belgium—a state that was finally achieved in the early 1990s. This article provides a first selective overview of Geys’s photo-based work and shows how his specific use of the medium corresponds with the basic principles on which his oeuvre is built.