In this chapter, we will explore the dark side of interpersonal communication. Communication often results in positive outcomes, but communication may also result in hurt, conflict, psychological damage, and relationship termination. The dark side of interpersonal communication generally refers to communication that results in negative outcomes. Some types of communication that are considered to be on the “dark side” are: verbal aggression, deception, psychological abuse, bullying, and infidelity, to name a few. For many years, communication scholars failed to focus on the more negative aspects of communication, but in doing so, overlooked opportunities to create solutions for those who are on the receiving end of this type of communication and for those who are the source. This chapter will explore destructive behaviors in relationships and negative communication strategies. Awareness of these negative communication strategies may be the first step in preventing these strategies.