Lying, defined as a conscious attempt to deceive someone, is typically done by children to protect themselves from punishment, bolster their self-esteem, hurt someone they dislike, help someone, or manifest a personality disorder. Underlying causes of lying are failure to learn standards of truthfulness and truthful behavior, fear and anxiety, lack of self-confidence and self-esteem, pathological lying due to serious personality disturbances, habits learned and difficult to break, and concern for another person. Lying can be prevented by teaching children standards of truthfulness early in life and helping children deal with fears and anxieties without resorting to pretense or fantasy. Other means of preventing lying are to foster self-esteem and self-confidence through a loving environment and opportunities for achievement as well as making clear those limited instances when lying is an acceptable way of benefiting another person. Treating children who lie involves combining efforts by many individuals to relieve the symptom based on earlier or current causes. This article recommends a three-pronged approach that addresses the causes of lying, personality defects that lead to lying, and modification of the habit of lying. A 14-item bibliography