The 38-year-old veteran ex-Arsenal shot-stopper's decision comes after Germany lost the UEFA European Championship final to Spain. Lehmann recently left Arsenal for Bundesliga side VfB Stuttgart.
He took the decision after a meeting with Germany coach Joachim Low and goalkeepers' coach Andreas Koepke, indicating that he would like to free the way for a younger goalkeeper ahead of qualifiers for the 2010 FIFA World Cup.
The UEFA EURO 2008 final on June 29 in Vienna was Lehmann's last appearance for the Mannschaft. He was capped 61 times for Germany.
Germany have a friendly against Belgium in Nuremberg on August 20 and begin their FIFA World Cup 2010 qualifying campaign against Lichtenstein on 6 September.