Purpose: The purpose of this study was to determine the personal hygiene behaviours of ninth and tenth grade students in the Bat&#253;kent Health Center No.1 district in Ankara. Material and Method: The study is of the cross-sectional type, with a universe of 1253 students, from which 236 students were selected by random sampling method. Among the chosen children, 94.3% of the ninth graders and 93.7% of the tenth graders were attained. The data was collected using a questionnaire form under observation. The questionnaire form consisted of 47 questions. A total hygiene score was calculated by giving 0 point to the incorrect answers and 1 point to the correct answers for the personal hygiene questions. The maximum score in the study was 37 and the minimum was 14. Results: 99.1% of the students have stated that they wash their hands with water and soap. 91.7% of the students stated that they brushed their teeth when they got up, 92.5% after meals and 95.7% before going to bed. The average hygiene score of males was 26.27 and that of females was 27.83 and the average of all students was 27.11. Total hygiene score was significantly associated with the educational level of the mothers (p<0.05). Conclusion: It was demonstrated that the ninth and tenth grade students of the high school where the study has been conducted have insufficient personal hygiene behaviours.