Rasmussen made his debut for the senior Danish national team on 11 October 2008, as he played the last 13 minutes of the 3–0 win against Malta in the 2010 World Cup qualification. In January 2009, he was a part of the unofficial Denmark League XI national football team which won the 2009 King's Cup invitational tournament, under the management of Danish national coach Morten Olsen.
Rasmussen first appeared for Denmark's senior national squad on 11 October 2008, playing the final 13 minutes of their 3–0 victory over Malta in the 2010 World Cup qualifying rounds. In January 2009, he was part of the unofficial Denmark League XI team that won the 2009 King's Cup tournament under coach Morten Olsen.