Josep Maria Sostres (1915-1984) is usually associated with a few works built in Catalonia, most of them on a small or domestic scale. While his production was far more extensive than as depicted in publications, he is associated nevertheless almost exclusively with a few emblematic works, such as the houses Casa Moratiel and Casa Agustí or the headquarters for the newspaper El Noticiero Universal. Some of his other projects, of greater size and complexity, were frustrated after months or even years of work. Many of these were produced at the beginning of his career, such as a Hotel in Montseny (1949-1954), and with which he continued working even when the commission failed, or the preliminary studies for a casino-theatre (1952-1953), which also was never constructed. One of the most unique and least examined of his works comprises several drafts, never published, for the Pedralbes campus of the University of Barcelona, located along Avenida Diagonal, then called Avenida del Generalísimo Franco, in the Les Corts district of the city. Sostres worked on the scheme at the beginning of the 1950s, at a time when this important urban project was still undergoing gestation and architecture competitions for the various faculties and residential colleges were being held. However, Sostres never submitted any entries to these, even though some thirty preparatory drawings for them have been preserved. The unpublished documents found in the historical archives of the Col·legi de Arquitectes de Catalunya reveals Sostres’s intense work on the campus project, the location for which was the subject of heated discussions during the early 1950s. Grup R, a group of Catalan architects formed at that time, as well as the Official Architects’ Association of Catalonia (Colegio Oficial de Arquitectos de Cataluña, COAC) conveyed several complaints to the authorities at the time, as they considered the choice of location to be unfortunate, in what was then a periphery of Barcelona, as well as located on both sides of the wide avenue, something that would prevent campus unity. Despite the proposed alternative locations, Sostres drew up several general plans for the Pedralbes area, and also a first draft for the Sciences Faculty. The degree of development of his proposals only allows here for an analysis of their volumetric articulation and relationship with the site, especially with Avenida Diagonal, but not the particular aspects of their interior organization. From both the general approaches and the concrete proposal for the Sciences Faculty one can derive an idea of the city for that particular area, an idea that resumed what had been planned for Pedralbes already at the beginning of the century yet never consolidated, as indeed is evident in the present state of the campus.