As well as being important tools for information acquisition, children's questions can also lead to profound learning. Nevertheless, no scale for measuring their questioning tendencies has hitherto been developed. Accordingly, this study pioneers one for use with preschool children. To establish construct validity, data from 544 children were used in exploratory factor analysis, and from an additional 237 children in confirmatory factor analysis. Of the original 25 questions, 10 were eliminated, and the remaining 15 items had a three-factor structure that explained 67.59% of the total variance. The internal consistency coefficient of the final Questioning Tendencies Scale was 0.894, establishing it as a valid and reliable instrument for use with children aged three to six.