This meta-analysis examined whether training improves detection of deception. Overall, 30 studies (22 published and 8 unpublished; control-group design) resulted in a small to medium training effect for detection accuracy (k = 30, gu = 0.331) and for lie accuracy (k = 11, gu = 0.422), but not for truth accuracy (k = 11, gu = 0.060). If participants were guided by cues to detect the truth, rather than to detect deception, only truth accuracy was increased. Moderator analyses revealed larger training effects if the training was based on verbal content cues, whereas feedback, nonverbal and paraverbal, or multichannel cue training had only small effects. Type of training, duration, mode of instruction, and publication status were also important moderators. Recommendations for designing, conducting, and reporting training studies are discussed.