Objective: To determine the prevalence and severity of malocclusion and orthodontic treatment needs among Tanta secondary school students and to analyze the relationship with gender and type of school. Methods: The study followed the World Health Organization recommendations for oral health surveys. Stratification of the sample was performed according to the district, type of school, and gender. The sample comprised 668 school students (290 males and 378 females) using the indexed age of 15 years. Mean, standard deviation, minimum, and maximum of DAI scores were calculated. Also, data were analyzed with regard to gender and school type using the chi-square test. Results: 78.7% of the examined students had normal occlusion with no treatment indicated. Meanwhile, students with definite, severe, and handicapping malocclusion in need of elective, highly desirable, and mandatory orthodontic treatment accounted for 14.1%, 4.2%, and 3% respectively. The mean DAI score of all the examined students was 22. There were no statistically significant associations between gender or school type and the severity of the malocclusion (p>0.05). Conclusion: the present results emphasized that the majority of secondary school students have normal occlusion while those with severe or handicapping malocclusion represent minorities.