"Her health is simply not good enough," Peter Englund wrote on his blog.
"All parties - including Mrs Munro herself - regret this, but there is no way around this," he wrote.
The Swedish Academy could not get hold of Munro before announcing the winner last Friday, but when Englund finally reached her several hours later, she indicated she probably would not be able to go.
"I'm an old woman, and my health is frail," she told Englund according to his blog.
Two recent female laureates, Doris Lessing (2008) and Elfriede Jelinek (2004), received their prizes at the Swedish embassies in their respective home countries.