This study was designed to assess oral health knowledge, attitudes and practices among secondary schools students in Sana'a city, Yemen. A cross-sectional questionnaire-based study was conducted on (1000) of secondary school students, (500) male students and (500) female students with an age ranged from 16-19 years. A selfadministered structured questionnaire consisting of 24 questions on socio-demographic data, oral health knowledge, attitudes and practices was distributed and collected data was subjected to statistical analysis. The mean knowledge scores for the secondary school students was 72.27 with a statistically significant difference between males and females (P = 0.001). Nearly 75.5% of them reported that regular visits to the dentist are necessary. In contrast, nearly (60.3%) of them visited the dentist when they felt pain and toothache was the most leading reason provided for visiting the dentist (62.1%). Moreover, nearly 42.9% of them reported that fear of needles and drilling was the major reason for their fearing of visiting the dentist. The use of toothbrush and paste was the most oral hygiene method used (78.6%). About 44.6% of them brushed their teeth once per day and 36.8% of them spent one minute for brushing their teeth. Nearly 44.3% of them reported that the time of tooth brushing was before going to bed only. Finally, most of them (74.1%) reported that their parents advised them about the importance of oral hygiene without their watching and did not supervise them. It showed that the students had good oral health knowledge. However, their oral health knowledge, attitudes and practices were bitter in female students than male students.