In the present study it was investigated to what extent observers (i) could make rapid yet reliable and valid judgements of the frequency of verbal and nonverbal behaviours of interviewees (liars and truth tellers) and (ii) detect deceit after making these rapid judgements. Five observers watched 52 videoclips of 26 liars and 26 truth tellers. The findings revealed that rapid judgements were reliable and valid. They also revealed that observers were able to detect truths and lies well above the level of chance after making these rapid judgements (74% accuracy rate was found). The implications of these findings for deception researchers and lie detection are discussed.