The objectives of this study were to evaluate the frequency and severity of the malocclusion and treatment needs in Peruvian young adults. The second aim was to compare the orthodontic treatment needs according to sex and socio-economic status (SES). This cross-sectional study was conducted at the University Dental Clinic of a private university in Lima, Peru. A total of 267 freshmen (from 16 to 25 years old) were randomly selected from a pool of 780 students. Students wearing an orthodontic appliance or reporting a history of orthodontic treatment were excluded from the study. Clinical examinations were conducted using the Dental Aesthetic Index (DAI). Mann-Whitney and Kruskal-Wallis tests were used to compare the DAI scores according to sex and SES, respectively. The mean DAI score was 28.87 points (IC(95%) 27.77; 29.97, where IC indicates interval of confidence). Around one-third of the sample presented severe or very severe malocclusion, which implies a highly desirable or mandatory orthodontic treatment need. No statistically significant difference was found between the DAI scores according to sex (P = .592) and SES (P = .397). Approximately one-third of the evaluated Peruvian young adults would need orthodontic treatment according to the DAI. In this population, malocclusion was characterized by a relatively high frequency of missing teeth, appreciable dental crowding, and inadequate anteroposterior relationships.