On 13 September 1796 Boi was appointed Associate Professor by royal decree, and on 16 March 1799 he was made Professor of Anatomy.
Although the chair of anatomy had been founded in 1764, until Boi was appointed it had been filled by professors from other disciplines.
Boi lectured at Cagliari for three years, but there were few students enrolled in the faculty.
In 1801 he therefore asked for permission, which was granted, to visit other universities to continue his study of anatomy.
Boi first visited the University of Pavia, where the famous anatomist Antonio Scarpa (1752-1832) was the professor of anatomy, and then the University of Pisa
before going on to Florence. There was no university in Florence, but there was a flourishing school of anatomy at the Hospital of Santa Maria Nuova under Paolo Mascagni (1755-1816), whose friend Felice Fontana (1730-1805) was the founder and director of La Specola Wax Museum.
Charles Felix (1765-1831), the younger brother of King Victor Emmanuel I of Sardinia (1759-1824), financed Boi during his stay in Florence.
Boi began to study anatomy in Florence under Mascagni. He initially assumed his maternal name of Pirisi, but his skill and knowledge of anatomy soon became apparent, and he was forced to reveal himself. He began a close collaboration with Mascagni, with whom he formed a deep friendship.
It was during these years that he worked with the sculptor Clemente Susini at La Specola in preparing wax anatomical models for teaching purposes.
Charles Felix had commissioned Boi to help prepare the models, for which Boi undertook the dissections that Susini then reproduced in wax.
Charles Felix purchased the wax models for his Museum of Natural History and Antiquities at considerable expense.
In 1805 Boi returned to Cagliari, where he resumed teaching, bringing the wax models with him.
In 1818 he was appointed Minister of Health of the Kingdom of Sardinia, which included not just the island of Sardinia but also the territories of Liguria, Piedmont and Savoy.
In 1824 he was knighted.
On his retirement in 1844 he was made a professor emeritus of the faculty.
He died in Cagliari on 15 May 1850.