
Background: Good oral hygiene is believed to be the result of level of knowledge of the individuals about the oral health and its great importance. Low level of knowledge results in poor oral hygiene practices. Objectives: The objective of this study was to assess the level of knowledge of secondary school students in Ajman, UAE, and its association with age, grade of study and nationality. Materials and Methods: A cross sectional study was conducted, among 175 children of grades 6-9 in the emirate of Ajman located in the United Arab Emirates. The students were selected conveniently from one school after obtaining permission from parents. The data was collected using a self-administered questionnaire which consisted of different sections that focused on the knowledge of the participants with regard to oral hygiene. The frequencies and percentages were obtained from the data and inferential statistics was applied to find the association between dependent and independent variables using SPSS 21 version. Results: All the participants reported that they’re aware of the importance of brushing. Among all participants, 148 (84.6%) reported that teeth should be brushed twice daily, and 82 (46.9%) reported soft brush to be used for brushing the teeth. Regarding the frequency of change of brush, 118 (67.4%) mentioned that the brush should be changed every 3 months and 62 (35.4%) mentioned 2 minutes brushing. Regarding the appropriate way of brushing 25 (14.3%) reported that brushing is to be done in vertical motion. The perception of participants on oral hygiene showed that 157 (90%) perceived that brushing teeth is very important (good score >=7). According to the overall rate on oral hygiene, 156 (89.1%) of the participants rated their oral hygiene as good (good score >=7). It was observed that age, grade and nationality did not show any statistically significant influence on participant’s knowledge on brushing and on their knowledge on importance of oral hygiene. Conclusion: In conclusion, good knowledge was observed regarding importance of brushing, frequency of brushing, and frequency of changing the brush whereas regarding type of brush to be used, duration of brushing, and appropriate way to brush the teeth the participants’ were lacking knowledge. Association between level of knowledge regarding oral hygiene and socio-demographic factors showed that the knowledge was more or less similar with regard to age and gender.