Human metapneumovirus (hMPV) is a recently discovered respiratory virus. hMPV, the second after respiratory syncytial virus (RSV), is leading cause of upper and lower respiratory tract infections mainly in infants and children. hMPV infections have been reported in many countries in all the world, in patients in every age and gender, but children under 5 years are most likely to be susceptible to infections caused by hMPV. The frequency of hMPV infections require hospitalization in this group is 5-10%. Late winter and early spring is the epidemic peak of hMPV infections in a lot of countries. The similar time of hMPV infections and another respiratory viruses is leading to appear coinfections. Many data reported higher frequency of double coinfections (RSV and hMPV), even 60-70%. This coinfections are responsible for 10-fold increase risk of admission children to a pediatric intensive care unit for mechanical ventilation. INF, AdV, PIV, EV are the other viruses cause coinfections with hMPV. The main laboratory method to diagnose hMPV infections is detect viral RNA and viral antigen in the sample.