Research aim: Translate the Malocclusion Impact Questionnaire (MIQ) from English into Croatian, adapt it and analyze the structure of the impact of malocclusion on adolescents. Study design: Cross-sectional study Materials and Methods: The forward-backward translation was made by four independent translators with good knowledge of both languages. A panel of five experts supervised the process and harmonized the Croatian version of the translation. The sample consisted of 254 individuals aged 10 to 18 years (median 15 years), of whom 52 % were female. The severity of dental malocclusion was determined by clinical examination using the Index of Orthodontic Treatment Need – Dental Health Component and Little's Irregularity Index. The subjects' satisfaction and treatment needs were assessed using a Likert scale (0 = not at all – 4 = very much), and the effects of malocclusion were assessed using the MIQ instrument, the Psychosocial Impact of Dental Aesthetics Questionnaire, and the Jaw Function Limitation Scale. Results: Factor analysis revealed that a unidimensional MIQ explained 46 % of the variance and had high internal consistency (Cronbach α = 0,920). The item biting food, correlated least with the other items, and if it were deleted, the consistency of the unidimensional structure would improve (α = 0,927). The MIQ correlated linearly more strongly with satisfaction with teeth and smile appearance (r = 0,575 and 0,411; p < 0,001) than with self-reported need for therapy (r = 0,421 and 0,366; p < 0,001). The impact of malocclusion was proportional to the severity of malocclusion (r = 0,321; p < 0,001), but not to the need for orthodontic treatment based on dental health. The MIQ correlated most strongly with the psychological and sociological effects of dental esthetics (r = 0,762 and 0,740; p < 0,001) and was not correlated with chewing limitations bite. Conclusion: The unidimensional MIQ has satisfactory psychometric properties and is a good measure of the psychological and social impact of impaired dental esthetics, but not of oral function.