Objectives: Assessing perception and attitudes about oral health and preventive dentistry among middle and secondary school students at public schools in Buraidah, Qassim, Kingdom of Saudi Arabia. Materials and methods: Systematic random sampling technique was applied to choose a total sample of 1,496 male and female students. Students were enquired to fulfill an anonymous self-administered questionnaire consisting of 42 questions at the same meeting. Students were asked on oral health and preventive dentistry. Statistical analyses were carried out at significance level <0.05 and 0.01. Results: Statistically significant difference was found between male and female students concerning their knowledge about oral health. Male students had poor awareness than females about "dental caries and oral conditions" and "dental health" (t test = 2.890*, p = 0.004) and (t test = 4.447*, p = 0.004), respectively. For perception about preventive dentistry, female students had statistically significant poorer acquaintance about "Dental sealants for caries prevention" and "Concept of preventive dentistry" than males (t test = −4.868*, p = 0.000) and (t test = −4.385*, p = 0.000), respectively. Moreover, middle school students demonstrated statistically significant lack of awareness about all types of oral health comparing to secondary school participants (t test = 20.774*, p = 0.000), (t test = 29.699*, p = 0.000), (t test = 23.061*, p = 0.000), and (t test = 25.802*, p = 0.000). For preventive dentistry, poor insight was showed among middle school students compared to secondary school participants for the categories "fluoride as a preventive measure" (t test = 20.367*, p = 0.000), "Prevention of oral and dental diseases" (t test = 15.924*, p = 0.000), and "concept of preventive dentistry" (t test = 29.928*, p = 0.000), while secondary school students were statistically unaware about "dental sealants for caries prevention" (t test = −4.699*, p = 0.000). Conclusion: Perception about oral health among the participants was generally poor.