The charity, which works to raise awareness of the continuing scourge of slavery around the world, is preparing for an advertising campaign in 2007 to mark the bicentennial of the abolition of slavery.
Saatchi & Saatchi has been briefed to create a campaign that not only raises funds for the charity, but also increases awareness of slavery, a practice that still affects more than 12 million people worldwide.
As well as focusing on the Transatlantic Slave Trade and slavery in countries such as the Philippines, the charity also targets the problems of people trafficking in the UK.
Anti-Slavery International was founded in 1839, and is the world's oldest international human rights organisation.
Aidan McQuade, the director of Anti-Slavery International, said: "We are excited to be working with Saatchi & Saatchi.
"Its proven record of cutting-edge creative and simple messages plays an important role in making the public aware of the legacies of the Transatlantic Slave Trade and of the need for the UK Government to take action against trafficking today."