Purpose: To assess the impact of different types of malocclusions on the quality of life in 18-year-old young male adults. Materials and Methods: A cross-sectional survey with a randomly selected sample of 414 young male adults who applied for military service in the city of Florianópolis in 2003 was carried out. Data on malocclusions were obtained through the dental aesthetic index variables. The impact of the oral health conditions on the quality of life was assessed, using the Oral Impact on Daily Performance index. Chi-squared tests were performed and the malocclusions statistically associated with the impact were included in models of unconditional multiple logistic regression. Results: The incisal crowding [OR 2.6 (95%CI 1.4-4.8)] (p = 0.002) and the anterior maxillary irregularity greater than 2 mm [OR 2.5 (95%CI 1.3-4.7)] (p = 0.006) had an impact on 'smiling, laughing and showing teeth without embarrassment'. An overjet measure greater than 5 mm [OR 3.7 (95%CI 1.2-11.2)] (p = 0.021) had an impact on 'maintaining emotional state without being irritable'. The molar relationship did not have an impact. Conclusions: Some types of malocclusions have an impact on quality of life, especially in terms of satisfaction with appearance. Keywords: epidemiology, impact, malocclusions, self-perception, young adults