The Tuskegee Syphilis Study was a notorious unethical medical experiment that took place in Tuskegee, Alabama, from 1932 to 1972. The study was conducted by the United States Public Health Service in collaboration with the Tuskegee Institute (now Tuskegee University) to study the progression of untreated syphilis in African American men.

The study involved 600 African American men, 399 of whom had previously contracted syphilis and 201 who served as a control group. The men were told that they were receiving free medical care for "bad blood," a term commonly used to describe a variety of ailments in the African American community at the time. However, the men were not informed that they had syphilis, nor were they given adequate treatment for the disease, even after penicillin became a widely available and effective treatment in the 1940s.

The study was unethical on multiple levels, including the failure to obtain informed consent from the participants, the withholding of treatment for a potentially fatal disease, and the exploitation of a marginalized population. The Tuskegee Syphilis Study became a symbol of the systemic racism and unethical practices that have pervaded the history of medical research in the United States.

The study led to the creation of ethical guidelines and regulations for human subjects research, including the requirement of informed consent and the establishment of institutional review boards to oversee the ethical conduct of research studies. The Tuskegee Syphilis Study also sparked conversations about racism and discrimination in healthcare and research, leading to improvements in protections for research participants and a greater awareness of the importance of diversity and inclusion in medical research.