This study examined young children's deception in a conflict situation. A puppet show was prepared involving a protagonist who went into hiding, an enemy who wanted to catch the protagonist, and a friend who was looking for the protagonist. In the no-conflict condition, the enemy asked the children about the location of the protagonist. In the conflict condition, the friend asked the children; however, the enemy was nearby and could eavesdrop. Thus, there was a conflict between deceiving the enemy and telling the truth to the friend. In Experiment 1, the enemy hid behind a tree and was not visible to the friend; 80 children aged 4, 5, and 6 years old participated. In Experiment 2, the enemy was visible to the friend but was disguised; 24 children aged 5 and 6 years old participated. Most 5- and 6-year-olds did not give accurate information to the enemy in the no-conflict condition. However, in the conflict condition, most of the children did not control their behavior and immediately gave accurate information to the friend although the enemy was nearby. Young children from the age of 5 years were able to deceive in the no-conflict situation, but it was difficult for them to deceive in the conflict situation.