In today’s increasingly complex and resource-constrained healthcare environment, managers are required to make decisions that are not only clinically sound but also strategically and financially justified. The business case has emerged as a critical tool to support this need for evidence-based, accountable, and value-oriented decision-making. This chapter explores the concept of the business case as both a methodological and strategic instrument tailored to the healthcare context. It defines the business case as a structured, evidence-informed argument used to justify specific investments, innovations, or organizational changes. Far from being a simple financial proposal, it integrates clinical, operational, technological, ethical, and political dimensions to guide decision-makers toward rational and sustainable choices. Through concrete examples—from implementing digital solutions to evaluating the continuation of existing services—the chapter demonstrates how business cases foster cross-disciplinary communication, prioritize competing initiatives, and ensure alignment with institutional goals. It highlights their relevance in both public and private healthcare systems, particularly in light of the growing emphasis on value-based care. Additionally, the chapter addresses the role of healthcare managers not only as authors of business cases but also as critical appraisers and contributors, underscoring the necessity of developing competencies in strategic planning, economic evaluation, and persuasive communication to effectively lead service innovation and transformation.