In the 1980s, Piot participated in a series of collaborative projects in Burundi, Côte d'Ivoire, Kenya, Tanzania, and Zaire. Project SIDA in Kinshasa, Zaire was the first international project on AIDS in Africa and is widely acknowledged as having provided the foundations of science's understanding of HIV infection in Africa. He was a professor of microbiology, and of public health at the Prince Leopold Institute of Tropical Medicine, in Antwerp, and at the University of Nairobi, Vrije Universiteit Brussel, the Lausanne, and a visiting professor at the London School of Economics. He was also a senior fellow at the University of Washington in Seattle, a scholar in residence at the Ford Foundation, and a senior fellow at the Bill & Melinda Gates Foundation.