NASA's Joe Acaba and Mark Vande Hei and Russia's Alexander Misurkin spent 168 days aboard the ISS.
A capsule carrying two US astronauts and a Russian cosmonaut from the International Space Station landed in Kazakhstan on Wednesday after a 168-day mission.
The Soyuz spacecraft brought back NASA's astronauts Joe Acaba and Mark Vande Hei and Alexander Misurkin, from Russian space agency Roscosmos.
A NASA TV live broadcast showed the capsule landing in the snow-covered steppe some 140 kilometres southeast of the central city of Zhezkazgan at 8.31 a.m. (0231 GMT).
Misurkin was the first to emerge from the spacecraft, assisted by members of the Russian search and recovery team, followed by a smiling Acaba.
The trio had spent five-and-a-half months at the ISS, a $100 billion lab that flies about 400 km above Earth.
They are due to be replaced by NASA's Andrew Feustel and Richard Arnold, and Oleg Artemyev of Roscosmos, whose spacecraft will blast off from the Baikonur cosmodrome, also in Kazakhstan, on March 21.