Elvis firm all shook up by legal defeat.
Three Court of Appeal judges rejected a challenge by EPE, of Memphis, Tennessee, to an earlier court ruling in favour of Mr Sid Shaw, who runs a memorabilia shop called Elvisly Yours.
Mr Shaw, who used to run a shop from Shoreditch High Street in London's East End and has now moved to the Trocadero in the City's Piccadilly Circus - selling articles from watches to toiletries that bear the singer's name - won a ruling from a High Court judge in March 1997 that EPE did not have the sole right to the legend's name.
EPE took their case to the Court of Appeal, challenging the decision by Mr Justice Laddie that a star's name, whether living or dead, cannot be used as a trademark.
His judgment led to rejection by the Trade Mark Registry of an application to register Diana, Princess of Wales.
Mr Shaw, speaking after Lords Justices Simon Brown, Morritt and Robert Walker dismissed the appeal in London, said: "In history David beat Goliath once - I have had to do it twice.
"I'm delighted. I've proved that Elvis belongs to all of us - Elvis is part of our history, part of our culture.
"Hopefully, the fans will start to support me and buy my souvenirs because Elvis souvenirs are tomorrow's antiques."
In rejecting EPE's appeal, Lord Justice Simon Brown said there should be no "assumption that only a celebrity or his successors may ever market or licence the marketing of his own character.
"Monopolies should not be so readily created."
EPE was refused leave to appeal to the House of Lords by the three judges, but it can still apply directly to the Law Lords themselves to hear the case.
When Mr Justice Laddie gave his ruling he said: "Even if Elvis Presley was still alive, he would not be entitled to stop a fan from naming his son, his dog or goldfish, his car or his house `Elvis' or `Elvis Presley', simply by reason of the fact that it was the name given to him at birth by his parents."
During the subsequent appeal hearing, Mr Peter Prescott QC, counsel for EPE, told the judges that the case raised a point of "some wide commercial importance in the trademark world".
He said: "It is the question of the famous name, which is sought to be registered as a trademark.
"We say it raises a paradox because there could be no doubt that if Elvis Presley had remained an obscure person from Tupelo, Mississippi, or indeed had never gone into music at all, his name Elvis, Elvis Presley and his signature would be regarded as distinctive trademarks which would be registered without any difficulty.
"We say that conclusion is incorrect.
"We say that the fame of Elvis Presley does not detract from the registerability of his name - if anything it would enhance it.
"That is the central point of the appeal."
But, the Court of Appeal upheld Mr Justice Laddie's findings.
Mr Shaw's wrangle with Elvis Presley Enterprises began 17 years ago after it objected to his products, some of which were being sold as souvenirs at Graceland, Elvis's home in Memphis, where the American company is based.
The head of EPE is Priscilla Presley, the singer's widow, who is the legal inheritor of his estate.