Fans strolled quietly through the Mediation Garden at Graceland, Presley's longtime Memphis, Tennessee, home. Presley's grave is in the garden, and his mother, father and grandmother are buried there.
The home is now a museum and a centerpiece of the Graceland tourist attraction that draws about 500,000 fans each year from around the world.
People began arriving early in the day to get a spot in line outside Graceland's gates. Tourists also watched Elvis tribute artists sing and dance, and visited gift shops and Elvis-related exhibits across the street from the home.
The scene is repeated each year on the anniversary of the death of the King of Rock 'n' Roll. Presley died at age 42 on Aug. 16, 1977, of a heart attack, shocking and saddening his fans worldwide.
Mark Summers, 31, said it was his first time attending the vigil. Summers, of Birmingham, England, is an Elvis tribute artist who performs theater shows across Europe.
Summers wore a black shirt, black pants and a hairstyle shaped like a pompadour, just like his idol. He said no other performer "could touch the charisma he had on stage."
Summers said he admired Presley not only for his music and his act, but also for his good qualities as a person. Presley was known for giving money to charities and cars to fans.
"So generous, caring, loving, spiritual, all those kinds of things," Summers said. "Tonight is going to be really emotional."
The vigil is a highlight of Elvis Week, an annual celebration of Presley's career and his life. This year, other Elvis Week events have included an auction of authenticated Presley artifacts - which included a 1977 Cadillac Seville used by Presley - and the groundbreaking of a planned 450-room hotel at the Graceland tourist attraction.