Little is known about how and when preschoolers master the concept of teaching, particularly in relation to the acquisition of theory of mind (ToM). We investigated the relationship between the two in children aged 3-6 years old. One hundred and seventeen French preschool pupils answered questions about different teaching situations illustrated in ten stories involving knowledge differences and/or false belief. Four change-of-location ToM stories were also administered. Our results indicate a developmental progression from understanding teaching situations to grasping the notion of knowledge gaps. Moreover, they confirm that ToM seems to be involved in understanding more complex teaching situations. (Contains 2 figures and 5 tables.)