Objectives:To investigate asthma prevalence and to measure asthma symptoms among Saudi adults in Riyadh, Kingdom of Saudi Arabia.Methods:A cross-sectional survey using the European Community Respiratory Health Survey (ECRHS) questionnaire carried out between April and June 2016, among male and female Saudi nationals aged 20-44 years living in Riyadh. Disproportionate cluster sampling method was used. Asthma was defined based on answering “yes” to any of the following: Have you had wheezing when you did not have a cold in the last 12 months? Have you been told by a physician to have asthma? Are you taking medicine for asthma?Results:A total of 2,405 participants completed the survey. The prevalence of wheezing in the last 12 months when not having a cold was 18.2% with no significant difference between males and females (p=0.107). The prevalence of physician-diagnosed asthma was 11.3% with no significant difference between males and females (p=0.239). The prevalence of taking medicine for asthma was 10.6%. There were no significant differences between asthmatic vs. non-asthmatic in terms of residency area (p=0.07), education level (p=0.11) and smoking tobacco (p=0.06). However, significant differences found between asthmatic and non-asthmatic in relation to nasal allergies (p<0.001).Conclusion:Asthma prevalence is high and much higher than the prevalence reported in most countries using the ECRHS questionnaire.