After taking the oath of office, Insulza asked for all member nations to work together to form "a more effective OAS."
The election of former Chilean interior minister to head up the OAS was filled with controversy.
Last month Insulza and Mexican Foreign Minister Luis Ernesto Derbez were locked in a dead heat for the position. In five separate ballots, the candidates both received 17 votes.
Derbez -- who was the United States' preferred candidate -- then bowed out of the race.
Insulza has already received the condemnation of Cuban leader Fidel Castro who earlier this month called him an "idiot" after he called for the advancement of democracy and protection of human rights in Cuba.