OBJECTIVE: Subsequent to a global outbreak of the Middle East Respiratory Syndrome (MERS) in 2012, a novel human coronavirus, known as Corona Virus Disease 2019 (COVID-19) has caused a major disease outbreak. The aim of this study was to perform a systematic review to compare epidemiological, clinical, and laboratory features of COVID-19 and MERS-COV populations. MATERIALS AND METHODS: We searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials database to identify potential studies that have reported COVID-19 or MERS-COV disease. Epidemiology, clinical, and laboratory outcomes, intensive care unit (ICU) admission rates, discharge rates, and fatality rates were evaluated using Graph-Pad Prism software. RESULTS: A total of forty-two studies were included in our research, involving in 4,720 patients (COVID-19 = 2,012, MERS-COV = 2,708). The present study revealed that main clinical manifestations of both COVID-19 and MERS-COV populations are fever, cough and generalized weakness or myalgia, and Acute Respiratory Distress Syndrome (ARDS) is the main complication. The COVID-19 population has a lower rate of ICU admissions, discharges, fatalities, and shorter incubation periods than those of MERS-COV population. CONCLUSIONS: The main clinical features of both COVID-19 and MERS-COV populations are fever, cough and generalized weakness or myalgia. ARDS is the main complication of both populations. COVID-19 cases have a shorter incubation period and lower rate of ICU admissions, discharges and fatalities compared to MRES-COV population.