Teaching others effectively may rely on knowledge about the mind as well as self-control processes. The goal of this investigation was to explore the role of theory of mind (ToM) and executive function (EF) in children's developing teaching skills. Children 3.5-5.5 years of age (N = 82) were asked to teach a confederate learner how to play a board game and were administered multitask batteries of ToM and EF with mental age, sex, and memory capacity as controls. There was a developmental increase in children's teaching skills (e.g., older children taught longer, explained more rules, and used more strategies when teaching). Examined separately, both ToM and EF explained unique variance in teaching skills over and above controls. Taken together, EF was a significant predictor of teaching efficacy over and above ToM and controls, whereas the same did not hold true for ToM. These results suggest that ToM may be a necessary prerequisite for teaching to occur; however, EF skills appear to play a vital role in children's teaching efficacy.