Dusautoir captained France to the 2011 Rugby World Cup Final against the hosts New Zealand, in which he scored France’s only try (one of two for the entire game) in the 47th minute (New Zealand’s Tony Woodcock scoring the other for the All Blacks) and made 22 tackles, for which he received the Man of the Match award. On the night of the final, one could hear chants of “Dusautoir” coming from the many bars showing the game around the Auckland waterfront. He was named the 2011 IRB International Player of the Year, thus becoming the second player from France to win the award after former captain Fabien Galthié in 2002. Dusautoir won the award over players such as Jerome Kaino and Ma’a Nonu.

He made his debut for France in a test against Romania on 17 June 2006 at Cotroceni Stadium in Bucharest, Romania, which saw France defeat the Romanians 62–14 and Dusautoir scoring a try on his debut. He played in the subsequent match against the Springboks at Newlands Stadium in Cape Town with France again emerging as the victors. He left Biarritz and signed for Toulouse in 2006.

He is perhaps most famous for his try against New Zealand in the quarter final of the 2007 World Cup in Cardiff in which he famously made 38 tackles, two more than the entire All Blacks side. He was nominated for world player of the year solely on this performance. His second-half score helped France to a 20–18 victory over the tournament favourites, despite the fact that he was not in the original 30-man squad and was only called up as a replacement for the injured Elvis Vermeulen. He also captained France to a famous 27–22 win over New Zealand in Dunedin on 13 June 2009. He has been linked with Leinster Rugby where he would replace Rocky Elsom.

In an interview on Total Rugby in July 2012, Dusautoir spoke about a perceived lack of respect towards his team during the 2011 World Cup. He cited a particular picture from the New Zealand Herald in the week leading up to the Final which showed Sonny Bill Williams and Israel Dagg laughing during training, with the caption ’80 minutes before laughing’. Dusautoir also shared about how France’s uncomplicated game plan in the Final nearly resulted in a memorable upset:

On 21 October 2012, in a Heineken Cup match against Treviso, Dusautoir twisted his knee in a tackle, suffering a twisted lateral ligament with a slight tear. The injury is expected to sideline him for four to six weeks, meaning that he would miss the 2012 November Tests.

On 11 January 2013, Dusautoir was named in the initial training squad for the 2013 Six Nations Championship, but Saint-André decided to retain Pascal Papé as captain in order to give Dusautoir time to ease his way back into the international team.