Virtually all fiscal measures can (or have the potential to) influence people’s health, through shaping behaviour, consumption, income and wealth. A subset of fiscal measures, however, can be identified as more directly linked to improving health by targeting behaviours and risks that are known to be strongly associated with health outcomes. Some of these measures, which we define as ‘health taxes’ in this book, have existed for a long time, although only in recent years have they been consistently framed as means of improving the health of individuals and populations. Taxes on alcoholic beverages have existed for over two millennia, for example, starting in ancient China. But these taxes have mostly been used to raise public revenues and control some of the detrimental social consequences, or negative externalities, of alcohol use. As evidence of the adverse health impacts of alcohol use has been consolidating, the rationale for alcohol taxation has increasingly focused on health promotion and improvement, and today alcohol taxes are widely used worldwide as health taxes.The narrative of health taxes began with the concept of ‘sin taxes’ on sugar, tobacco and alcohol. A focus on the taxation of ‘unnecessary’ consumption goods has been reflected in the work of economists since Adam Smith’s widely quoted statement ‘sugar, rum, and tobacco are commodities which are nowhere necessaries of life, which are become objects of almost universal consumption, and which are therefore extremely proper subjects of taxation’.1 The classical rationale for taxing such commodities was to raise the revenues necessary for collective use without interfering with essential forms of consumption. The work of Frank Ramsey,2 a century ago, added the concept that efficient commodity taxation requires a focus on goods whose demand is not sensitive to price changes, holding firm the principle in Adam Smith’s quote. Arthur Pigou further strengthened the rationale for commodity taxation by linking it to negative externalities, or socially undesirable consequences not reflected in the market price, that are associated with the production or consumption of the goods to be taxed.3Products that today we know are associated with poor health outcomes happen to have all these characteristics: they are not necessities, their demand is relatively insensitive to price and they generate negative externalities. The fact that such commodities have been taxed long before evidence of their health impacts emerged makes it possible to pursue health goals in fiscal policies simply by repurposing existing taxes, that is, adapting their design to ensure they generate meaningful health impacts; it is not necessary to identify new objects of taxation.