in 2009, koufos debuted with the senior greek national basketball team, and he competed at the eurobasket 2009, where he won a bronze medal. during the eurobasket 2009 tournament, he averaged 5.6 points and 3.0 rebounds per game. he also played at the eurobasket 2011, where he averaged 8.7 points and 3.7 rebounds per game. koufos also competed at the eurobasket 2015, where he had his best tournament with the senior greek national basketball team, as he averaged 10 points and 6.6 rebounds per game, in 8 games played.