The former FC Koln and Hansa Rostock signed a one-year deal with the Iranian Football Federation (IFF) on Saturday, Mehr news agency reported.
The Iranian squad left for Oman on Sunday to take part in a four-team friendly tournament. Iran will play its first match in the tournament against Ecuador on December 16.
After the Oman tournament, Iran's national team will fly to Spain for two more friendly games.
Rutemoller, who is also the Technical Director of the German Football Association, is expected to join the national team in Spain as he is currently in Bulgaria.