Throughout history it has been assumed that lying is accompanied by specific nonverbal behaviors; various sources still claim that nonverbal behavior is very revealing about deception. Systematic research, however, examining nonverbal cues to deceit has shown that nonverbal cues to deceit are faint and unreliable. This chapter starts with discussing under which circumstances people pay attention to nonverbal behavior and provides reasons why they do so. This is followed by a theoretical background of nonverbal cues to deception and discussions of the (weak) empirical evidence about (1) the relationship between nonverbal cues and deception, including the empirical evidence regarding the Behavior Analysis Interview and Ekman’s approach of observing facial expressions, and (2) people’s (poor) ability to detect deceit when paying attention to nonverbal behavior. Despite the popularity of observing nonverbal behavior to detect deception, analyzing speech content provides more accurate results, particularly when specific interview protocols are used.