This policy paper, published by the Center for Global Development, qualitatively establishes the complex costs and benefits of strengthening laboratory capacity and systems within and across national borders. Costs are presented as direct and indirect, while benefits are presented at the individual, population, and health-system levels. Each cost and benefit grouping is further divided into thematic subcategories. This paper demonstrates that investments in laboratory systems can yield considerable and wide-ranging benefits. While these investments require comprehensive financing, their impacts are potentially transformative.