 The World Health Organization's choosing interventions that are cost-effective, WHO choice, program has been running for over 20 years, during which time it has analyzed the cost effectiveness of 479 interventions across two regions, eastern sub-Saharan Africa and Southeast Asia. This newest update presents the results of a cross-regional analysis of these interventions, finding that they range from very low to extremely high cost-effectiveness ratios. The analysis also found that interventions targeting multiple diseases and risk factors were more likely to be cost-effective than those targeting just one. Additionally, the analysis identified a set of interventions that could provide the greatest overall health benefit at the lowest cost. These interventions include those focused on primary care and prevention services, such as immunizations and screenings. This article was authored by Melanie Y. Bertram, Jeremy A. Lauer, Karen Stenberg, and others.