"The Olympic Charter states that the Olympics should seek to foster 'respect for universal and fundamental ethical principles,'" the California Democrat said in a statement. "Sadly, the Chinese government has not lived up to its commitments to improve the human rights situation in China and Tibet."
She said she believed the International Olympic Committee "made a mistake" in awarding the games to China and sponsored a congressional resolution outlining her view at the time.
"However, I believe a boycott of the Beijing Olympics would unfairly harm our athletes who have worked so hard to prepare for the competition," Pelosi said.
When the Olympic torch passes through San Francisco next month, Pelosi said she would support people speaking out about the actions of the Chinese government.
She said she told the Dalai Lama when they met in India, "If freedom-loving people throughout the world do not speak out against China's oppression in Tibet, we have lost our moral authority to speak out on behalf of human rights anywhere in the world."
Puzzle-maker slips 'Murdoch Is Evil' into Rupert Murdoch's Sunday Telegraph
Sign language interpreter at Mandela service called out as fake on Twitter