"I think they (Facebook) have proven - by not taking down something they know is false - that they were willing enablers of the Russian interference in our election," The Hill news magazine quoted the California Democrat as saying.
Pelosi was referring to a doctored video of her that had been slowed down to make her appear to be slurring her words or intoxicated. The video was posted on Facebook last week and has since been viewed more than 2.8 million times.
Facebook decided not to remove the video, but told The Hill that its fact-checkers had flagged the video as false and were downgrading its distribution in the Facebook news feed.
A Facebook spokesperson defended the decision before a group of international lawmakers in Ottawa, Canada, on Tuesday, saying: "It is our policy to inform people when we have information that might be false on the platform so they can make their own decisions about that content."
Pelosi said on Wednesday that while she "can take it", her issue was with Facebook "lying to the public" by allowing the video to stay up.
She added that Facebook not taking down the doctored video called into question the company's assertion that it was the victim of Russian online interference that was meant to sway the 2016 presidential election.
"We have said all along, 'Poor Facebook, they were unwittingly exploited by the Russ'," Pelosi said. "I think wittingly, because right now they are putting up something that they know is false. I think it's wrong."
( With inputs from IANS )