He was Invited to Iran national under-17 football team in 2005.
In 2006 AFC U-17 Championship, he worn number 14 and was a benchwarmer.
Ansarifard played as a substitute in two matches against Tajikistan and Yemen.

Karim Ansarifard made his debut against Iceland in November 2009 under Afshin Ghotbi and scored his first international goal and the only goal of the game.
He was given the legendary number 10 previously worn by Ali Daei and scored on 15 January 2011 his 3rd international goal against North Korea, so Ansarifard became Iran's youngest ever goalscorer in the AFC Asian Cup.
In 2014 FIFA World Cup qualification, Ansarifard scored a double against Maldives at Azadi Stadium.
He came on as a late substitute against Uzbekistan in the World Cup Qualifiers and assisted with a beautiful pass for Mohammad Reza Khalatbari as a 94th-minute winner.
On 1 June 2014, he was called into Iran's 2014 FIFA World Cup squad by Carlos Queiroz.
He played his first World Cup match against Bosnia and Herzegovina, coming on as a substitute for Ashkan Dejagah in the 68th minute.
He was called into Iran's 2015 AFC Asian Cup squad on 30 December 2014 by Carlos Queiroz.
He provided an assist to Sardar Azmoun in their Asian Cup preparation match against Iraq.
In May 2018 he was named in Iran's preliminary squad for the 2018 World Cup in Russia.
He scored a penalty against Portugal with a 1–1 as the result.
He was Invited to Iran national under-17 football team in 2005. In 2006 AFC U-17 Championship, he worn number 14 and was a benchwarmer. Ansarifard played as a substitute in two matches against Tajikistan and Yemen.
Karim Ansarifard made his debut against Iceland in November 2009 under Afshin Ghotbi and scored his first international goal and the only goal of the game. He was given the legendary number 10 previously worn by Ali Daei and scored on 15 January 2011 his 3rd international goal against North Korea, so Ansarifard became Iran's youngest ever goalscorer in the AFC Asian Cup. In 2014 FIFA World Cup qualification, Ansarifard scored a double against Maldives at Azadi Stadium. He came on as a late substitute against Uzbekistan in the World Cup Qualifiers and assisted with a beautiful pass for Mohammad Reza Khalatbari as a 94th-minute winner. On 1 June 2014, he was called into Iran's 2014 FIFA World Cup squad by Carlos Queiroz. He played his first World Cup match against Bosnia and Herzegovina, coming on as a substitute for Ashkan Dejagah in the 68th minute. He was called into Iran's 2015 AFC Asian Cup squad on 30 December 2014 by Carlos Queiroz. He provided an assist to Sardar Azmoun in their Asian Cup preparation match against Iraq. In May 2018 he was named in Iran's preliminary squad for the 2018 World Cup in Russia. He scored a penalty against Portugal with a 1–1 as the result.
Karim Ansarifard