To successfully pull a practical joke on someone, children need to understand that their victims do not know what they themselves know, be able to intentionally manipulate others' beliefs, and maintain a straight face to safeguard the integrity of the joke. This study examined the relationship between children's developing theory of mind (ToM), inhibitory control, and their ability to pull a practical joke. Ninety-five children between ages 2 and 6 participated in, among other measures, a practical joke task that required them to knowingly give one of the experimenters a gift box containing a rubber insect. Results showed that children's ability to pull a practical joke was significantly related to their age, false belief understanding (FBU), inhibitory control, and verbal ability. Children with more siblings were more likely to successfully pull a practical joke. Most importantly, inhibitory control was shown to mediate the relation between FBU and practical joking. The findings provide evidence that practical joking as an example of ToM use is effortful.