Background: To assess malocclusion status among 12-15 year old school children using Dental Aesthetic Index and to compare severity of malocclusion and treatment needs among males and females. Methodology: A cross-sectional study was carried out to assess the malocclusion status of 12 to 15 year old school children of Mangalore city, Karnataka, India. Study subjects comprised of 918 school children of Mangalore city. Consent was obtained from the parents and assent was obtained from all the participants before examination. Malocclusion status was recorded using DAI index. The data obtained was coded and fed into the SPSS version 16 for analysis. Results: The study population consisted of 918 children aged 12 to 15 years with 47.7% being males and 52.3% being females studying in schools of Mangalore city, Karnataka, India. Minor malocclusion with no or slight need for treatment was prevalent in 72.2% of the study subjects, definite malocclusion requiring elective treatment was present in 16.2% of the participants, while 7% and 4.2% of them had severe and handicapping malocclusion respectively. Conclusions: 27.7% of the children were in need of orthodontic treatment. The severity of malocclusion and orthodontic needs were more among this group of population. This information is relevant for planning preventive measures. Keywords Malocclusion, Dental Aesthetic Index, School Children, Treatment needs