COVID-19 is an infectious disease caused by a newly discovered coronavirus. Most patients infected with the COVID-19 virus experience mild to moderate respiratory symptoms and heal without any special treatment. This survey aimed to assess the knowledge of Syrian and Saudi populations about the general information, symptoms, and methods of prevention of coronavirus (COVID-19). Materials and Methods: A standardized questionnaire composed of four sections (demography, general information about COVID-19, symptoms of COVID-19 infection, and methods of prevention) including 34 questions divided between the four mentioned sections were sent online to different social media in the Syrian Arab Republic and Kingdom of Saudi Arabia as a Google drive form. The collected data were coded, computerized, and analyzed using methods of descriptive statistics by SPSS 25. A Chi-square test was done. Results: The total number of participants was 790; most of them were in the age group of 18–30 years (60.3%) wherein females formed about 59.2% of the whole sample. About 94.6% of the respondents from Syria agreed that several coronaviruses are known to cause respiratory infections while 45.6% of Saudi people knew that diarrhea is one of the symptoms of coronavirus (COVID-19). The good results of this current study were clear in the section of coronavirus (COVID-19) prevention as most of the information was correct in more than 60% of answers. Conclusion: The knowledge of Syrian and Saudi populations about the general information, symptoms, and methods of prevention of coronavirus COVID-19 was very good to excellent except in very limited points.