The 16-year-old American said the aftermath of her surprise win in Salt Lake City had left her no time to train.
"Winning the world championships is one of the goals I have set for myself,» Hughes said in a statement released by the US Figure Skating Association.
"Unfortunately, while the past two weeks have been terrific, they have also been very exhausting and have not afforded me the opportunity to properly prepare for the competition."
"I plan to spend the summer working to improve my skating, and look forward to competing next year at the highest level possible"
Hughes is not the only Olympian skipping the championships, being held in Nagano from 18-24 April.
Canada's Jamie Sale and David Pelletier, awarded duplicate gold medals after a French judge admitted she had been pressured to put a Russian pair first, withdrew last week.
Hughes pulled off one of the biggest upsets in Olympic history when she won the women's free skating on 21 February.
She beat Irina Slutskaya of Russia and six-time US champion Michelle Kwan.
Hughes also did the toughest technical programme, becoming the first woman to complete two triple-triple combinations at an Olympics.
Since then, she's popped up at the Grammy Awards and on numerous TV shows.
She visited the floor of the New York Stock Exchange, where she rang the opening bell. She also visited with Mayor Michael Bloomberg and got a key to the city.
But, unlike Tara Lipinski, who turned pro shortly after winning the gold medal at the Nagano Games, Hughes said she plans to keep her Olympic eligibility.
"I plan to spend the summer working to improve my skating, and look forward to competing next year at the highest level possible," she said.