Purpose: The aim of this study was to assess the relationship between untreated malocclusions and oral health-related quality of life (OHRQOL) in male adolescents of Mashad (Iran) high schools. Materials and Methods: In this observational cross-sectional descriptive study, 120 male students were randomly selected among Mashad (Iran) high schools. These students filled out an oral health-related quality of life questionnaire (the modified version of CPQ), and then they were clinically examined to determine their malocclusions according to the Index of Complexity, Outcome and Need (ICON), and finally the relationship between these two variables was assessed with the Pearson correlation test. Results: There was a statistically significant relationship between ICON scores and the quality of life levels (P 0.01). The assessment of four sections of the questionnaire showed that among these four sections (oral symptoms, functional limitations, emotional well-being, social well-being), only oral symptoms were significantly correlated with the ICON score (P 0.05). Conclusion: Malocclusion plays an important role in the oral health-related quality of life. However, the relationship between emotional well-being, social well-being and malocclusions was not as strong as in previous studies. Keywords: adolescent, index of complexity, malocclusions, oral health-related quality of life, outcome and need (ICON)