Three X-rays of the screen siren's chest and pelvis, taken during a 1954 hospital stay drew the monster bid, h was more than 10 times the pre-auction estimate.
Auction house Julien's said in a statement that the sale was part of an auction of Hollywood Legends memorabilia which took place at the Planet Hollywood Resort and Casino in Las Vegas. The images had been displayed in Ireland, Japan and China before finally going under the hammer.
Monroe died in August 1962 at the age of 36.
Other items also sold at the auction included a chair from Monroe's last photo shoot that went for $35,000, Christopher Reeves' Superman VI costume which sold for $32,500 and a dress worn by Audrey Hepburn in "Funny Face" which went for $56,250.