Agency theory has proved to be useful as a theoretical and empirical lens for examining a wide range of issues in business to business markets. This chapter attempts to explore the current and potential (future) applications of agency theory in business markets. First, the chapter explains the major constructs embedded in agency theory, the assumptions underlying the theoretical structure, and the classes of problems to which this structure is inherently well suited. Next, the key characteristics of business to business marketing are discussed, as well as the demands that these characteristics impose on incumbent theories which seek to shed light on business markets. Following, the the range of issues in business markets to which agency theory might be productively applied is outlined, along with modifications/extensions required to accommodate unique features of these markets. Finally, emerging areas of interest are reviewed, identifying promising areas for future research.