This study tested a physiologically based arousal theory of deceptive communication. The sympathetic activation (skin resistance) of three groups of communicators was monitored. Two of the groups, deceivers and unaroused truth tellers, paralleled the types of communicators used in earlier deception studies; and a third group, aroused truth tellers, was exposed to a noise stimulus to raise their sympathetic activation to a level comparable to deceivers. Comparison of the behavioral differences between comparably aroused deceivers and truth tellers made it possible to identify the cues unique to deception-induced arousal. Results confirmed that deceivers experienced significantly greater sympathetic activation than unaroused truth tellers. Six verbal and nonverbal behaviors reliably distinguished deceivers from unaroused truth tellers, and, most important, these same six behaviors reliably distinguished deceivers from aroused truth tellers.