Trained at the School of Medicine and Surgery of Pistoia. In 1835, while still a student, he submitted a major paper to the Società Medico-Fisica Fiorentina announcing the discovery of the digital-nerve corpuscles that now bear his name. Studied histology and conducted research on cholera. Was the first to see and draw the vibrio described as the cholera pathogen by Robert Koch (1843-1910) in 1884. Named professor of anatomy and histology at the Istituto di Studi Superiori of Florence in 1847. Also studied the physiology of the muscle system and perfected the microscope to meet his personal research requirements. Pacini's manuscripts are deposited at the Biblioteca Nazionale Centrale of Florence.