H5N2 is a subtype of the species Influenzavirus A (avian influenza virus or bird flu virus).

A highly pathogenic strain of H5N2 caused flu outbreaks with significant spread to numerous farms, resulting in great economic losses in 1983 in Pennsylvania, USA in chickens and turkeys, in 1994 in Mexico in chickens and a minor outbreak in 1997 in Italy in chickens.

It was reported on November 12, 2005 that "One of 2 birds found infected with bird flu in Kuwait has the H5N1 strain of the virus, authorities said. The infected bird was a migrating flamingo found on a Kuwait beach. The other was an imported falcon found to have the milder H5N2 variant."

In China, inactivated H5N2 has been used as a vaccine for H5N1.

Japan's Health Ministry said May 11, 2006 that 93 poultry farm workers near Tokyo may have been exposed to H5N2 (which was not previously known to infect humans) in 2005. "Preliminary tests on the workers were positive for H5N2 antibodies, indicating they were previously exposed, Takimoto said. While exposure carries with it the possibility of infection and illness, he said none had tested positive for the virus itself or had developed flu symptoms. [...] About 5.7 million birds have been destroyed in Ibaraki following the H5N2 outbreaks."

In 2006, an H5N2 outbreak on a single farm in South Africa resulted in the destruction of all its sixty ostriches. The strain was similar to the one that caused outbreaks in South Africa 2004/2005.

In 2007, a low-pathogenic strain of H5N2 was found in samples collected from 25,000 turkeys in Pendleton County, West Virginia in a routine testing prior to their slaughter. The birds showed no sign of illness or mortality. Measures were taken to prevent the virus from mutating and spreading.

In late 2007 (December 21), an H5N2 outbreak was found in the Dominican Republic, in a Suburb of Higuey City, on the eastern side of the island. 15 roosters and 2 hens where eliminated even though they had no visible sign of infection.