Coronaviruses were discovered in the mid-1960s then at 2002 in Foshan, China a new virus discovered to cause a Severe Acute Respiratory Syndrome (SARS-CoV) then at 2012 another strain was identified in Saudi Arabia causing the Middle East Respiratory Syndrome (MERS). In December 2019 in Wuhan, Hubei, SARS-CoV-2 (COVID-19) emerged to spread as pandemic. Being a series of the same family, the current research aimed to compare the characteristics of COVID-19 in relation to SARS and MERS regarding the origin and genomic structure, mode of transmission, distribution of cases along the world countries, infectivity and mortality rates together with the clinical presentation, diagnosis and treatment.