Objectives: The purpose of this study was to develop and appraise an oral health literacy assessment tool for upper elementary school students. Methods: Twenty-eight preliminary assessment items were developed on the basis of various types of oral health education literature for children. They contained verbal and functional sections and they were classified into 2 cognitive processes (literal and inferential). The questionnaires were analyzed using the testAn v.1.0 program for identified Cronbach`s a, item discrimination, and difficulty through classical test theory. A final evaluation tool was developed and selected by conducting three surveys and 20 items. Results: The final survey was completed by 132 fifth and sixth grade elementary school students in Seoul. The Cronbach`s a value, item discrimination, and difficulty were .71, .38, and .75, respectively. The mean score for oral health literacy of children was 14.9 (±3.2, theoretical range: 0-20, 75% correct answers). Conclusions: These results suggest that this tool could be relied on to help determine the level of oral health literacy in children and in preparing appropriate oral health education programs for children.