Assou-Ekotto made his debut for Cameroon against Guinea in a friendly match on 11 February 2009. He also played the full 90 minutes in Cameroon's 1–0 surprise 2010 FIFA World Cup Qualifying defeat to Togo on 28 March 2009. He was named in Cameroon's 2010 Africa Cup of Nations squad but was forced to withdraw prior to the tournament due to injury. Assou-Ekotto was also named in Paul Le Guen's final 23-man roster for the 2010 World Cup in South Africa and played every minute of Cameroon's three matches.