"If I'm emotional it's because I'm finishing my rugby playing career at the end of the season," he told a press conference.
"It's a very special moment, charged with emotion for me but not sadness as I'm going to be enthusiastically pursuing a new opening which I've begin to develop, a second life as a businessman."
Dusautoir joined Toulouse in 2006 and won the French championship with the club in 2008, 2011 and 2012. He was part of the team that won the European Cup in 2010.
He first donned a France shirt in 2006 and one year later burst onto the world stage at the 2007 World Cup, making his name against New Zealand in the quarter-final with a try and 29 tackles. His heroics that day lifted France to a famous 20-18 win and earned him the nickname "The Dark Destroyer".
Dusautoir was named World Player of the Year in 2011 after leading his country to the World Cup final against New Zealand. He brought the curtain down on his 80-cap career with France after their 62-13 loss to the All Blacks in the 2015 World Cup quarter-finals.
Reflecting on his career in rugby, he said: "The decision one day to come along and put on boots and a pair of shorts literally changed my life and turned a timid kid into one who had confidence in himself. This sport has changed my life and I owe it a great debt."
He added: "I never thought I'd go on to have the career that I did."
Dusautoir said that in his post rugby life, he would put more time into developing his digital marketing and food import-export companies.