[1] Pacini was born in Pistoia, Tuscany, to Francesco, a humble cobbler, and Umiltà Dolfi, but was given a religious education in hopes that he would become a bishop.

He studied them closely from 1833 on, and first discussed them in 1835 at the Società medico-fisica in Florence, but did not publish his research ("Nuovi organi scoperti nel corpo umano") until 1840.

Immediately following the death of cholera patients, he performed an autopsy and with his microscope, conducted histological examinations of the intestinal mucosa.

John Snow, who disproved the miasma theory, and Robert Koch, were widely and erroneously credited with the discovery of the bacillum 30 years later.

Pacini spent most of the money remaining after his scientific investigations on the long-term care of his two ailing sisters, Assunta and Maria Giustina.