"I will be 83 years old on December 12," Barker said Tuesday as he revealed his decision to retire this coming June. "I've decided to retire while I'm still young."
Though he has been considering retirement for "at least 10 years," Barker said he has so much fun doing the show - the longest running game show on television - that he hasn't been able to leave.
"I've gone on and on and on to this ancient age because I've enjoyed it," he said. "I've thoroughly enjoyed it and I'm going to miss it."
Barker said reaching the dual milestones of 50 years on television and 35 with "Price" makes this an "appropriate" time to retire. Hosting the daily CBS program — in which contestants chosen from the crowd "come on down" to compete onstage for "showcases" that include trips, appliances and new cars — is "demanding physically and mentally."
"I'm just reaching the age where the constant effort to be there and do the show physically is a lot for me," he said. "I might be able to do the show another year, but better (to leave) a year too soon than a year too late."
Leslie Moonves, president and CEO of CBS Corporation, said Barker has left an enduring mark on the network, calling his contribution and loyalty "immeasurable."
"We knew this day would come, but that doesn't make it any easier," Moonves said in a statement. "Bob Barker is a daytime legend, an entertainment icon and one of the most beloved television personalities of our time."
He's got a lot of trophies to prove it: 17 Emmys, 13 of which are for his work as host - more than any other performer - and he's been in the Television Hall of Fame since 2004.
Barker was born in Darrington, Washington, but spent most of his youth on the Rosebud Sioux Indian Reservation in South Dakota, where his mother was a schoolteacher.
The family eventually moved to Missouri, where Barker attended high school and then college on a basketball scholarship.
He was a Navy fighter pilot in World War Two, but the war ended before he was assigned to a seagoing squadron.
Barker began his national television career in 1956 as the host of "Truth or Consequences" - one of television's first shows and one of the most popular, running on and off in various versions from 1950 to 1988.
And he was a guest panelist on another of television's most famous quiz shows: The Match Game.
Barker has tried his hand at other things, saddling up with Little Joe and the gang on "Bonanza" in 1960, and sometimes accepting guest spots on sitcoms, soaps and talk shows.
But America loves him best when he is master of ceremonies.
He's done it on numerous shows, from "Circus of the Stars" to "Miss Universe," but nothing can compare to his record-setting run on "Price" - a dream show for producers with relatively low costs and merchants, with a great chance to showcase their wares as contestants size up what they hope will be their big haul.
Barker first appeared on "Price" on Sept. 4, 1972, and has been the face of the show ever since.
Even before Barker's big announcement, a CBS primetime special celebrating the show's longevity and Barker's five decades on TV was already in the works, according to a spokesman for CBS.
To kick off his retirement, Barker said he will "sit down for maybe a couple of weeks and find out what it feels like to be bored." Then he plans to spend time working with animal rights causes, including his own DJ&T Foundation, devoted to the spaying and neutering of pets and named in memory of his late wife, Dorothy Jo, and mother, Matilda.
Barker said he'd take on a movie role if the right one came along, but filmmakers, take note: "I refuse to do nude scenes. These Hollywood producers want to capitalize on my obvious sexuality, but I don't want to be just another beautiful body."
Freemantle Media, which owns "Price," has been looking for Barker's replacement for "two or three years," Barker said. And he has some advice for whoever takes the job: learn the show's 80 games backwards and forward.
"The games have to be just like riding a bicycle," Barker said. "Then he will be relaxed enough to have fun with the audience, to get the laughs with his contestants and make the show more than just straight games, to make it a lot of fun."
As for his fans, Barker said he "doesn't have the words" to express his gratitude.
"From the bottom of my heart, I thank the television viewers, because they have made it possible for me to earn a living for 50 years doing something that I thoroughly enjoy. They have invited me into their homes daily for a half a century."
But when it comes to ringing down the curtain on "Price," Barker said he'll sign off the same way he always does, each and every day, with a message that's familiar to his many fans: "Help control the pet population. Have your pets spayed or neutered."