Just 10 percent of Americans approved of Congress in August, down six points from last month, and tied with February as the lowest rating in Gallup's 38-year history of the measure.
The approval rating has been below 20 percent every month since 2011. Before 2007, Congress's approval rating had been below 20 percent only twice -- in 1979 and 1992, according to Gallup.
"It is difficult to pinpoint precise causes for these extraordinarily negative views, although the continuing poor economy is certainly a major factor," Gallup reported on Tuesday.
It's unclear whether the public's disapproval of Congress will rub off on Rep. Paul Ryan, Republican presidential candidate Mitt Romney's vice presidential pick.