OBJECTIVE: To develop a questionnaire in English and Spanish to measure concerns caused by children’s (and their parents’) perceptions of dental appearance. MATERIALS AND METHODS: The questionnaire addressed concerns in the physical, mental, and social domains, perceptions about discolourations and other oral conditions including tooth colour. Test-retest and internal reliability, and construct and criterion validity, were assessed as part of the development process. Children in Mexico City, Mexico and Indianapolis, Indiana answered the questionnaire and were examined for fluorosis using the TSIF index. Data were analysed using Cronbach’s alpha, Pearson’s, Spearman’s and intraclass correlations, and percentage agreement tests. RESULTS: Ninety-five children and 28 parents participated in Mexico City; fluorosis was diagnosed in 66% of children. Seventy-one children and 65 parents participated in Indianapolis; fluorosis was diagnosed in 63% of children. English and Spanish questionnaires had acceptable test-retest performance, and moderate internal reliability. Criterion validity was acceptable, and the translated versions retained acceptable construct validity. Perceptions of discolourations were associated with concerns of the participants. Level of concern was higher in Indianapolis than in Mexico City, generally. Many participants reported that they were at least occasionally distressed or worried over the appearance of the children’s teeth, that it hindered children from smiling freely, and that it was an unsatisfactory appearance. CONCLUSION: The developed questionnaire allowed children and parents to report perceived dental appearance problems and concerns.