Background:  Asthma is one of the most common chronic diseases in children and adults. The prevalence of asthma has increased in developed and developing countries over the last three decades. Our objective was to estimate the prevalence of physician-diagnosed asthma and to describe some related characteristics and associated symptoms of cases in a sample of adolescent secondary-school girls of Riyadh city, Saudi Arabia. Methods: A descriptive cross-sectional study was conducted in secondary schools in Riyadh city, during the academic year 2016-2017. A predesigned questionnaire was disseminated to the targeted population to complete it. Results: Out of 154 female students, the prevalence of physician-diagnosed asthma was 4.5%. The prevalence of rhinitis symptoms, exercise-induced wheezing and night coughing in the past 12 months in physician-diagnosed asthma and exercise-induced wheeze was 42.9%, 28.6% and 28.6%, respectively. Conclusion and recommendations: The prevalence of physician-diagnosed asthma in female adolescents in Riyadh, Saudi Arabia was 4.5%, there was with a high rate (42.9%)of rhinitis symptoms among the asthmatic girls. The prevalence of asthma in Riyadh, Saudi Arabia was within the reported prevalence ranges from many other parts of the world. Health education sittings is recommended to increase the public awareness about the causes and importance of seeking medical care during and between the attacks of asthma, especially in adolescent period.