Background: Among women of reproductive age, polycystic ovarian syndrome (PCOS) is a common endocrine condition that has been linked to detrimental metabolic, reproductive, endocrine, and psychological effects. PCOS may be present among many girls who experience persistent irregular menstruation. The aim: Assess knowledge and practices regarding polycystic ovary syndrome at Assuit Secondary school students. Design: This study was carried out using a descriptive research design. Setting: This study was conducted at Assuit Nursing Secondary School female Students at Al-Eman General Hospital in Assuit city. Sample: A Convenient sample was recruited for this study of all available nursing secondary school students (190-all levels). Tools of data collection: Data were collected by using one tool. an interviewing questionnaire consists of three parts: Part (1): Personal data It includes: Age, residence, fathers' education, fathers' occupation, mothers' education, mothers' occupation. Part (2): Knowledge regarding PCOS. Part (3): Assess practices regarding PCOS. Results: The current study findings the mean age of studied ( ±16.82). This study shows (80%) of students had average knowledge about PCOS and (71.1%) of unsatisfactory practices. Conclusion: Four fifth of studied students had average knowledge on PCOS. More than two thirds of studied students were unsatisfactory preventive practices of PCOS. More than half of students unaware about PCOS. Recommendation: Implementing a programme to raise knowledge of young girls about polycystic ovarian syndrome and its practices to prevent PCOS.