After exhausting all their ammunition the pilots were leaving the scene when their helicopter came under fire from the ground near Palmyra city.
Two Russian pilots were killed in Syria after DAESH shot down a helicopter near Palmyra, the Russian military was quoted as saying by local media.
The two pilots, Riafagat Khabibulin and Yevgeny Dolgin, were flying a Syrian Mi-25 helicopter which was downed east of Palmyra city.
The Russian pilots were attacking DAESH in the Homs region on Friday on the request of the Syrian government.
After using up all of their ammunition the pilots were leaving the area when their chopper came under fire from the ground held by Syrian military troops after DAESH militants breached Syrian forces' lines east of Palmyra.
"The turning helicopter was hit by militants' gunfire from the ground and crashed in the area controlled by the Syrian government army. The crew died," the Russian military was quoted as saying by Interfax news agency.
Video footage released by DAESH affiliated news agency Amaq on Saturday showed a helicopter being shot and crashing to the ground against cries of "It's fallen, God is greatest".
The statement by the Russian defence ministry said that the two Russian pilots were on a test flight in the Homs region with a Syrian Mi-25 helicopter laced with ammunition.
The statement further said the Syrian government requested the pilots to carry out strikes against the DAESH militants.
Both the pilots have been nominated for Russian state awards.
Russian forces entered the conflict at the end of last year, backing the forces of Syrian regime.
Russia has so far lost at least 12 soldiers in the Syrian war.