The Tuskegee Study of Untreated Syphilis in the Negro Male, also known as the Tuskegee Syphilis Study or Tuskegee Syphilis Experiment (/tʌsˈkiːɡiː/ tus-KEE-ghee) was an infamous clinical study conducted between 1932 and 1972 by the U.S. Public Health Service studying the natural progression of untreated syphilis in rural African-American men in Alabama under the guise of receiving free health care from the United States government.
The Public Health Service started working on this study in 1932, in collaboration with Tuskegee University, a historically black college in Alabama. Investigators enrolled in the study a total of 600 impoverished, African American sharecroppers from Macon County, Alabama. Of these men, 399 had previously contracted syphilis before the study began, and 201 did not have the disease. The men were given free medical care, meals, and free burial insurance for participating in the study. After funding for treatment was lost, the study was continued without informing the men they would never be treated. None of the men infected were ever told they had the disease, and none were treated with penicillin even after the antibiotic became proven for the treatment of syphilis. According to the Centers for Disease Control, the men were told they were being treated for "bad blood", a local term for various illnesses that include syphilis, anemia, and fatigue.