Over three years, Harrison has become known for his tough-love appraisals of family heirlooms.
"Pawn Stars," "Early Show" co-anchor Harry Smith pointed out, is the biggest show the channel has ever had.
Harrison said he's surprised at the show's success. "I'm a nerdy guy who likes to read a lot," he said. "They came to me for a TV show and next thing, it's pretty successful."
He added, "I've done this my whole life. When I first started doing it, when I was like 13 years old, there was a lot of trial-and-error. 'What do you mean it ain't worth nothing?' But I've been doing it so long. I have markets to sell all this. I've got a reputation of being really honest and that's how -- all of a sudden all the stuff came in."
Harrison works with his family, which he says is the best and worst part about his business.
He explained, "I work with my father, who is my father. He was in the Navy 20 years. He's a strictly no BS guy. Then I have my son, who's young and really, really cocky, and I have to run a business with all that."
And his business he assured Smith isn't "Antiques Roadshow." He offers money at the moment you pawn.
"('Antiques Road Show' is the) best case scenario in an auction," he said. "They don't tell you about the auction fees, everything else. I'm cash on the barrel head, right then."
And he said his pawn shop isn't just about handing things over for money. He said his store still pawns for loans.
"The majority of my business is still pawns. Most of those who pawn things and want to borrow money don't want to be on television," he said. "That part of my business you don't see and I do five or 10 times as much."
Harrison also showed some of his great pawn finds, including an Apollo 11 patch that was in space, American money from the 1800s that featured great pieces of art, and a Russian Faberge brooch.
You can see "Pawn Stars," on the History channel every Monday night at 10:00 p.m. Eastern.