The New York Times broke the story in late April that Walmart's massive expansion in Mexico last year was lubricated by bribes to public officials.
The story said Walmart had conducted an in-house investigation into the bribes, then squashed its own findings.
Web site YouGov, which tracks public opinion on political issues and business brands, said Walmart's score dropped 15 points three days after the scandal was reported -- on a scale that goes from 100 down to minus 100.
But Walmart's score began returning to normal after the three-day drop.
"Walmart's Mexico bribery scandal might be causing the retailer some pain in the United States and may yet force personnel resignations, but other brands like Target and Taco Bell experienced significantly worse perception crises in the past 18 months and they took two months to mend," YouGov reported.
YouGov said the bribery scandal's hit to Walmart's reputation was "similar in magnitude to when it was hit with a class-action discrimination lawsuit," from which the chain took three weeks to recover.
In comparison, Walmart rival Target "received a much more significant consumer backlash in summer 2010 when it donated money to a controversial political group."
It took seven weeks for the public's opinion of Target to recover the 28 points it lost after the controversy involving a Target donation of $150,000 to a group that supported Tom Emmer's campaign for governor of Minnesota.
The donation was seized on by gay rights groups as a donation to an openly anti-gay candidate.