Background: Oral diseases have been a persistent public health problem globally, with almost every individual suffering from poor oral health at least once in their lifetime. Oral health problems affect 3.9 billion people globally. Dental caries, periodontal disease, and oral cancer are examples of common oral conditions that meet the requirements for being classified as public health issues. Oral health promotion through school is recommended by the World Health Organization (WHO) for improving knowledge, attitude, and behavior related to oral health and for the prevention and control of dental diseases among school children. Materials and methods: This school-based quasi-experimental study with nonequivalent group design was conducted between January and June 2022 among adolescent students from class V (5th year of school) to class X (10th year of school). The sample size was around 460. Oral self-examination was done once a month in each class of school by the teacher and also once a week in each class of school by a peer group. Results: The percentage of fathers’ education belonging to high school during the post-intervention phase in the intervention school and control school is 37 and 24.8%, respectively. The distribution of oral hygiene index simplified score (good) increased from 29.6 to 38.7% in the intervention school and the proportion of oral hygiene index simplified (poor) decreased from 20.4 to 20% in the intervention school. Conclusion: Schools offer a great environment for teaching about health issues, modeling healthy behaviors in them, connecting them with services, and interacting with parents and the community through the students, education is one of the most efficient ways to reach children and adolescents.