This work intends to offer an initial general overview of the correspondence of Ulisse Aldrovandi (1522-1605), mainly contained in the Fondo Aldrovandi of the University Library of Bologna. The Bolognese natural history scholar had in fact exchanged over 2,100 letters with correspondents from even geographically remote areas. Of the overall total of these letters, only a few have been published, while a significant percentage of letters remain unpublished to this day. However, the aim of the present research is not the edition of the letters, but an analytical study of the pre-eminent functions and characteristics of this correspondence examined in its entirety.