In this chapter, we discuss how interpersonal accuracy – the ability to accurately assess others’ states and traits – plays out in hierarchies, particularly those related to workplace and leadership. We begin by discussing the importance of interpersonal accuracy for workplace relationships, such as those with customers, co-workers, and among subordinates and superiors. Overall, the literature on this topic shows that interpersonal accuracy skills are associated with positive outcomes in workplace tasks such as sales and negotiations. Moreover, we summarize research that shows the positive outcomes associated with interpersonally accurate leaders. In the second part of the chapter, we summarize the theoretical issues and empirical research that investigate how power is related to interpersonal accuracy. Finally, we discuss research investigating the extent to which individuals are accurate in assessing others’ power or hierarchical positions, as well as the verbal and nonverbal cues they use. Overall, we show that there is mostly a positive relationship between power and interpersonal accuracy in the workplace context, and we highlight the limitations and possible future directions in this line of research.