Trochowski played for the German under-20 team at the 2003 FIFA World Youth Championship. One year after his move to Hamburg, senior national coach Joachim Löw called him for the first time, and he debuted on 7 October 2006 in a friendly against Georgia at the Ostseestadion in Rostock; he started the game and was replaced by Torsten Frings for the final 14 minutes of the 2–0 victory. After having appeared six times during the qualification matches, Trochowski was selected for the final 23-man squad for Euro 2008, but was unused as Germany reached the final. He scored his first international goal on 15 October 2008, the sole goal in a 2010 World Cup Qualifier against Wales in Mönchengladbach.