In 1987, Farmer, along with pals, Ophelia Dahl, Jim Yong Kim, Thomas J. White and Todd McCormack, co-founded Partners In Health (PIH). PIH began in Cange in the Central Plateau of Haiti and has developed into a worldwide health organization. The PIH hospital in Haiti provides free treatment to patients. PIH helps patients living in poverty to obtain effective drugs to treat tuberculosis and AIDS.
In addition to his hospital in Haiti, Farmer oversees projects in Russia, Rwanda, Lesotho, Malawi and Peru. His approach has it's basis in ethnographic analysis and real world practicality. Farmer is a co-founder and Board Member of the Institute for Justice & Democracy in Haiti.