Henderson, best known as the mom on "The Brady Bunch," flashed a smile and kissed her dance partner, Corky Ballas, immediately upon learning she had become the fifth competitor to be be voted off this season, based upon a combination of fan votes and judges' scores.
After kissing show host Tom Bergeron, she told him: "I've loved this show since it began. ... I hope I've inspired people to get up off their behinds and live and dance and enjoy life.
"What has surprised me the most," she added, "has been the intensity with which you have to work. We have not had a day off since we began."
Henderson, who at 76 was the oldest competitor in the show's 11th season, received straight sevens from the judges for her tango danced to the "Brady Bunch" theme song on a week when the other competitors also danced to TV theme songs.
"Parts of that tango were excellent," show judge Len Goodman told her, according to the "Dancing With the Stars" website. "A couple bits were a little bit too frantic ... but I think that's possibly your best dance so far."
Barry Williams, who played Henderson's TV son, Greg Brady, was a surprise guest on the show.
Henderson referred to Williams' past confession that he had crush on his TV mom.
"I'm not going to confirm or deny any kind of relationship," was Henderson's coy comment to camera.
Also in jeopardy of departing until the show's final minutes were actress Jennifer Grey and Rick Fox, the actor and former pro basketball player.
Grey, the first of the three to learn she would be returning, has regularly received top scores from the judges. Upon learning she was safe, she exchanged a high-five and a hug with her dance partner, Derek Hough.
Despite being voted off, Henderson was full of praise for "Dancing With the Stars."
"I have been in television for over 50 years," she said, "and I have to say, in all honesty, that this is one of the best produced shows I have ever been on."
She singled out members of the show's cast and crew, its judges, "and most of all, this darling man, Corky" -- referring to her dance partner.
In a voiceover segment after her departure, Henderson revealed why she loved the show so much.
"At my age, you can still be hot and sexy and mix it up," she said. "I feel like a kid again."
"It was surreal for me," she said. "It was like, 'I'm actually finally dancing on "Dancing With the Stars."'"
As the show closed and Henderson and Ballas embraced on the dance floor for a final time, Grey appeared close to tears.
ABC News' Eileen Murphy contributed to this report.