Hantaviruses are a group of segmented, negative-sense, single-stranded RNA viruses that commonly circulate in rodents without inducing overt clinical signs. However, accidental hantavirus infections in humans through inhalation of aerosolized rodent excretes may result in two serious clinical diseases namely hemorrhagicfever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS) or hantavirus cardiopulmonary syndrome (HCPS), depending on hantavirus species involved. Hantaviruses causing HFRS primarily occur in Europe and Asia (Old World) and employ rodents of the Murinae and Arvicolinae subfamilies for maintenance, while those causing HPS/HCPS are mostly found in the Americas (New World) and use rodents of the Sigmodontinae subfamily as reservoir. In order to implement effective control and prevention measures against HFRS and HPS/HCPS in human populations, it is vital to have the responsible agents correctly identied.