Between 1946 and 1948, American physicians conducted unethical medical experiments on around 1,300 Guatemalans without their knowledge or consent. These experiments involved deliberately infecting individuals with syphilis, gonorrhea, and chancroid—sexually transmitted diseases—under the guise of medical treatment. The participants, many of whom were prisoners, mentally ill individuals, or soldiers, were selected because they were considered vulnerable and less likely to challenge the procedures. The research, conducted in the name of science, aimed to test the effectiveness of penicillin in treating sexually transmitted diseases, but the methods used were extreme and unethical. The experiments involved methods that went far beyond what was considered acceptable at the time, including organizing sexual encounters between participants and infected sex workers, as well as directly injecting individuals with the diseases. Many of the victims were unaware they were part of a scientific study and believed they were receiving standard medical care. These actions were hidden for over six decades, largely because the research was not officially published, and the victims had little power to voice their concerns or seek justice. The scandal was uncovered in 2010 when researchers discovered documents detailing the experimental protocols. This led to the public revelation of the unethical practices and prompted the U.S. government to issue formal apologies to Guatemala. However, these apologies did not include any form of compensation for the victims. The issue of reparations remains complex, as it is difficult to establish direct links between the past infections and any current health effects, and legal challenges have complicated the process of providing redress. The Guatemalan experiments highlight serious ethical failures in medical research, including the lack of informed consent and the exploitation of vulnerable populations. The long period during which the experiments remained hidden underscores the importance of transparency and accountability in scientific research. While the U.S. government has acknowledged the wrongs committed, the full consequences of these actions continue to be felt by the victims and their descendants.