Carlos Queiroz has left his position as Iran head coach after four years at the helm.
The ex-Real Madrid boss took charge in April 2011 and led the nation to the 2014 World Cup in Brazil.
Iran also made the quarter-finals of the Asian Cup in Australia earlier this year, where they were defeated on penalties by Iraq.
Queiroz, a former Manchester United assistant coach, had signed a contract extension in September committing himself to the job until the 2018 World Cup.
However, following a 3-1 friendly defeat to Sweden on Tuesday, the Portuguese has opted to bring an end his tenure.
"After four years of work with the national team, I am proud of the team and the individual players," Queiroz said.
"Now I am sad to leave the team, but that's life and I'm happy to be moving forward."