Pavarotti was appointed a Messenger of Peace in 1998, and has raised money for many U.N. humanitarian causes.
The farewell tour, which comprises 40 appearances in cities throughout the world and which will run into 2006, will include United Nations promotional videos and public service announcements about HIV and AIDS awareness, children's rights, and poverty, among others.
"I am very proud both to be associated with the United Nations and to have been appointed a Messenger of Peace for this valuable and vital organization," Pavarotti said, "and will do whatever I can to help its work."
U.N. secretary-general Kofi Annan has called the tenor "a true friend of humanity." Pavarotti has previously organized concerts to benefit children in war-torn countries; his annual Pavarotti and Friends concerts have raised funds for welfare of refugee children from Afghanistan, Angola, and Iraq.