Recently unearthed records reveal that between 1946 and 1948, researchers with the US Public Health Service engaged in nonconsensual inoculation of vulnerable Guatemalan populations with syphilis, gonorrhea, or chancroid. The US government has issued formal public apologies to the Guatemalan government and its people, and the Presidential Commission for the Study of Bioethical Issues has been tasked with reviewing the historical record and the adequacy of protection of human research participants. We argue that the US response is insufficient and call for a restitution program directed at the aggrieved parties. We review the lessons of two earlier analogous cases and propose guiding principles upon which such a restitution program could be crafted with the Guatemalan people in mind.