Background Dental health is related to the general health of the individual. Dental caries is a highly prevalant oral disease particularly among children. We took high school students as the focus of our survey, as an approach to improve knowledge, attitude and practices of dental hygiene. The objective was to assess the impact of health education about oral health on knowledge, attitude and practice among high school students. Materials and methods A health educational interventional study was done among high school students using a questionnaire and the study was repeated after 2 weeks following health education. Result: The mean knowledge score before intervention was 4.02 with standard deviation of 2.29 and it increased to 9.00 with standard deviation zero. The attitude score before intervention was 1.8 with a standard deviation of 0.94 and it increased to 3.00 with a standard deviation of zero. The practice score before intervention was 6.06 with standard deviation of 1.78 and it increased to 9.78 with a standard deviation of 1.45. Conclusion This study demonstrated that a school based, educational intervention can be effective in improving oral health among school children.