It seems so obvious that good decisions on innovations in medical and hospital management – or on anything – should be based on good evidence. Decision-makers are advised by business school professors (and their mothers) that decisions should be based on the best available evidence – and who could argue against that? However, despite the general reverence for evidence in medical practice and drug approval, there is a consensus (discussed later in this chapter) that decision-making on medical delivery or insurance innovations – which also can have effects on health, life, death, and spending – is often not evidence-based, sometimes contradictory to evidence, and surely not as evidence-based as it could be. In this introductory chapter we explore two related questions: (1) what is the value of evidence for these decisions, and (2) where in health care management is evidence not being generated or used as it should be? This chapter will in a sense discuss “evidence on evidence,” and ask when and what kind of evidence is needed to improve not only decision-making, but also final outcomes in terms of spending and quality.