The statement added that article meant "readers around the world have now been led to believe that thousands of migrant workers in Qatar have perished, or will perish, building the facilities for World Cup 2022 - a claim that has absolutely no basis in fact".
The article, which was posted online on May 27, has been viewed more than five million times, said Qatar.
Doha says it wants the article corrected and retracted.
Qatar said it had written to the Washington Post to complain but was told because the "article had appeared online and not in print", the letter would not be published.
It said the Washington Post had taken the "total annual mortality figures for Indian and Nepalese migrants working in Qatar and multiplied those numbers by the years remaining between now and the 2022 World Cup".
Doha said the calculation made no distinction for how those deaths occurred.
On its website, the Post said the story had been "updated to reflect the fact that figures include total migrant worker deaths in Qatar, not just World Cup-related deaths".
-AAP