This article presents the vita of Antoni Brosz (1910-1978), a bibliophile and collector from Cracow, who was also a translator of Slavic languages. During about 40 years he completed a collection of exlibrises containing about 20000 signs altogether (including duplicates). In accordance with his last will, less than 16000 units (including about 10000 Polish signs and about 6000 foreign signs) were handed over to the Jagiellonian Library at the end of 1980. In 1999, the archival materials (including personal documents, letters as well as workshop notes) were also consigned to the Library. Antoni Brosz was the co-founder of the prewar Circle of Exlibris Lovers, which formed part of the Book Lovers Society. He participated actively in the Circle"s work and maintained contacts with numerous Polish and foreign collectors. He also collected so-called "Orkaniana", i.e. materials concerning Wladyslaw Orkan.