This investigation examined relationships between personality and nonverbal behavior displayed during heterosexual relationship initiation. Individuals were videotaped as they answered questions posed by an attractive opposite-sex “interviewer.” Raters then coded each individual′s nonverbal behavior on 11 behaviors and 34 global attributes. Men who were unrestricted in sociosexuality smiled more, laughed more, gazed downward less often, and displayed more frequent flirtatious glances than did restricted men. Unrestricted women were more likely to lean forward and cant their heads than were restricted women. Men who were extraverted, high self-monitors, and unrestricted in sociosexuality were rated as more socially engaging/dominant and phony. Extraverted women were rated as more engaging/dominant and phony, and high self-monitoring women were rated as more phony. Results are discussed from a human ethological perspective.