Born in 1800 into a farming family in Hizen province, he developed an interest in medicine and traveled to Nagasaki, where he was able to study medicine and Dutch language with Philipp von Siebold and interpreter Inomata Den'emon.
In 1828, he moved to Edo and established his own medical office there. Three years later, he became an official court physician to Saga domain, while maintaining his private practice. It is said that there was regularly a long line of patients eager to see him. At one time, Genboku was also invited by Shimazu Nariakira to come to Satsuma domain and to contribute to translation and other scientific efforts.
In 1849, the Tokugawa shogunate issued bans on Dutch Studies, Dutch medicine, and translation of Dutch books. Yet, at the same time, they invited Genboku to help run a private vaccination station established by the shogunate. The station was finally built in 1858, and was destroyed in a fire the following year. It was reestablished at Genboku's home the year after that, in 1860, and was shortly afterwards put under more direct shogunate control. It was renamed the Seiyô igaku sho (Office of Western Medicine), and Genboku became officially employed by the shogunate. The Meiji government retained him in a similar position, and this Office of Western Medicine later developed into the University of Tokyo School of Medicine.
- Plaque at grave of Itô Genboku, Tenryû-in, Yanaka, Tokyo.
- Honjin ni tomatta daimyô tachi, Toyohashi, Aichi: Futagawa-juku honjin shiryôkan (1996), 32.