Population Services International (PSI), the world’s leading non-profit social marketing organization. Population Services International (PSI) is a global nonprofit organization focused on the encouragement of healthy behavior and affordability of health products. PSI was founded in 1970 to improve reproductive health using commercial marketing strategies and has expanded to work in over 50 countries in the areas of malaria, family planning, HIV, diarrhea, pneumonia and sanitation. PSI is headquartered in Washington, DC. A hallmark of PSI is a commitment to the principle that health services and products.