Brocchi was educated in the classics and literature but also brought into contact with the outdoors by his father’s enthusiasm for hunting. He early developed strong interests in antiquities and natural history despite parental discouragement. Sent to the University of Padua to study law, he preferred the botanical garden and the lectures in botany by Bonato.
Upon the death of his father, Brocchi went to Rome, where he studied the art and monuments of antiquity intensively for six months. Returning to Bassano, he devoted himself to literature, especially the works of Dante, for two years.
In 1802 Brocchi became an instructor in natural history at the Gymnasium in Brescia. Appointment in 1808 as inspector of mines at Milan gave him the opportunity to travel widely through Italy, making extensive notes and collecting numerous specimens. The return of Lombardy to Austria in 1814 deprived Brocchi of this position but did not lessen his activity, which henceforth was centered in Rome. In 1821 he was restored to his position, but meanwhile, he had accepted the invitation of the viceroy of Egypt to conduct a survey of the mineral resources of that country and to organize its mining industry. In the fall of 1822, he sailed from Trieste to Egypt, whence he made excursions up the Nile, and into Syria and Palestine. In 1826, as he was preparing to return to Italy, he contracted bubonic plague, of which he died.
Brocchi published five major books and contributed about seventy articles to various journals. He wrote upon an amazing range of subjects from antiquities to zoology in carefully documented papers replete with classical references. While at Brescia he published zoological and mineralogical articles; these include observations on the anatomy of insect eyes and on infusoria. In 1818 he conducted experiments on "night air" at Rome, in the hope of finding the cause of malaria; the results were negative but duly reported. He also published several articles on recent shells.
Brocchi’s most significant contributions, however, were in the field of geology. Early papers such as the memoir on the Val di Fassa consist largely of mineralogical descriptions. The geognostical introduction to this report shows no appreciation of the stratigraphic significance of fossils beyond the uncertain importance of their presence or absence as criteria for "secondary" or "transition" rocks. The origin of basalts interbedded with limestones is discussed in terms of the Neptunist-Vulcanist controversy.
Brocchi’s masterpiece is the Conchiologia fossile subappennina (1814). It opens with an eighty-page survey of paleontological studies in Italy - a mine of historical data that has been freely used by Lyell, Zittel, and other writers. The nature of the fossiliferous deposits at various localities is described in detail. He noted the contrast between the Subapennine fossils, most of which could be identified with the living Mediterranean fauna, and those described by Lamarck from the Paris Basin, most of which were extinct. The possibility that deposits of greater antiquity have fewer living species is mentioned, but not examined in detail. A chapter is devoted to the problem of extinction.
This work was completed before William Smith had published on the stratigraphic significance of fossils, and probably before Brocchi had read Cuvier and Brongniart’s Essai sur la géographie minéralogique des environs de Paris (1811). It is doubtful whether knowledge of the chronological value of fossil shells would have enabled Brocchi to reach more fundamental conclusions concerning these deposits; nearly all his collections were from Pliocene deposits - indeed, they constitute much of the "type" Pliocene of Lyell.
Brocchi made his first extensive exploration of central Italy in 1811 - 1812. In the course of this, he witnessed an eruption of Vesuvius and was thus able to compare the state of its crater before and after an eruption. From 1814 until 1820 his work was largely on volcanic rocks, especially tuffs. Impressed by the wide distribution of certain ash beds around Rome and Naples, he argued for the submarine deposition of these even in the face of included freshwater fossils, which he insisted were transported. His descriptions of these deposits are thorough and accurate, and his De stato fisico del suolo de Roma (1820) still contains valuable data on the geology of the Imperial City. The Catologo ragionato (1817) likewise is a useful compendium of original observations on the geology of central and southern Italy.