Background: Adolescence is a crucial phase of life and encompasses a nice result on the adolescent period. It's a time once teenagers develop the information, attitudes and skills that facilitate them to become sexually healthy. Aim of the study: this study aimed to assess University females' knowledge regarding sexual health education. Method: Descriptive study was conducted among (585) adolescent girls registered at Mansoura university at the first, second and third years with, Mansoura University, Egypt. Data were collected using three tools; the first tool was a structured questionnaire which included socio-demographic data, second tool was self-administered questionnaire to assess university females' knowledge and cultural preferences, third tool was attitude scale to assess university females' attitude, the fourth tool was self- administered questionnaire to assess university female sexual health education methods and preferences. The study was conducted from August 2013to February 2014. Results: The mean age of the adolescent girls was 19±0.66 years; about three fourths were belonging to middle social class. The participants showed poor score level of knowledge in relation to definition and changes of maturation, wet dreams, masturbation, abnormal sexual behavior, sexual transmitted disease. The main sources of knowledge were friends, families, mass media and internet. Conclusion: The main conclusion drawn from the current study is that the majority of the adolescent girls had poor score level of knowledge regarding sex education. Recommendations: It was recommended to apply professional, comprehensive and individualized sex education focusing on improving the knowledge and increasing awareness of adolescent girls to improve their sexual health and prevent potential sexual transmitted diseases.