Infectious diseases (IDs) contribute to major causes of mortality and chronic morbidity in Central and South America. Interest in improving general understanding, prevention, and treatment options motivates the U.S. Department of Defense to establish and run overseas ID institutions to enhance force health protection. One of 6 Department of Defense overseas ID institutions, U.S. Naval Research Medical Unit (NAMRU) SOUTH, has safely and ethically conducted biomedical research, ID surveillance, and medical countermeasure testing and evaluation in Peru and surrounding countries. In its over 40-year history, NAMRU SOUTH medical research collaborations have achieved many milestones leading to critical ID information sharing, funding, services, and education mutually beneficial to the U.S. and regional partners in Latin America.