He began his bibliographical career by the preparation of several auction catalogues, notable examples being that of the Comte d'Ourches (Paris, 1811) and an 1802 supplement to the 1790 Dictionnaire bibliographique de livres rares of Duclos and Cailleau.

In 1810 the first edition of his bibliographical dictionary, Manuel du libraire et de l'amateur des livres (3 vols.

Brunet published successive editions of the dictionary, which rapidly came to be recognized as the first book of its class in European literature.

[1] The last of the 6 volumes of the 5th edition (1860–1865) of the Manuel du libraire contained a classified catalogue (French: Table Méthodique) in which the works are arranged in classes according to their subjects.

[2] He attributed to Aldus Manutius the first such bibliographic organization in his "Libri Greci Impressi" where the works were divided into "Grammatica, Poetica, Logica, Philosophia, Sacra Scriptura" (Grammar, Poesy, Logic, Philosophy, Sacred Scripture).