"It was a tough decision to take. The national team was my big goal when I was young, and since then it has been a big part of my life," Sorensen said in a statement.
"I'm 36 years old, and I have to admit that I notice the extra physical burden that an international player carries."
The Stoke City goalkeeper rarely looked back after replacing Peter Schmeichel at the start for the 2002 World Cup qualifying campaign. He went on to play at the 2002 and 2010 World Cups and Euro 2004.
However, Sorensen missed Euro 2012 due to a back injury he suffered in a warm-up friendly against Brazil in Hamburg in May, which turned out to be his last international.
Sorensen made his debut against Israel in 1999 and won his 100th cap against Russia in March.