The survey, taken last month, shows that 29 percent of Iranians view the U.S. positively. In February 2008, a similar poll of Iranians showed 34 percent with favorable views of the U.S.
But at the same time, support in both surveys remains strong for democratic institutions like free elections and a free press.
The survey was conducted for Terror Free Tomorrow and the New America Foundation, a pair of Washington-based groups.
Obama has said he is open to dialogue with Iran in hopes of improving relations with that country.