Market response models that include price as a variable are based on the assumption that consumers, when making their choice, know the price of the product that they select. This chapter discusses consumers’ price knowledge. It lays out different ways in which the concept can be defined and measured, and summarizes extant insights into how consumers acquire, store and update such knowledge. It then reviews the antecedents of consumers’ price knowledge, including the economic context, sociodemographics, consumer shopping habits, and characteristics of the product. The chapter concludes by identifying gaps in the literature that warrant future research.