The "Police Academy" and "Three Men & A Baby" star tells HuffPost Live he was offered the part of Fin, the shark-killing hero in the franchise eventually played by Ian Ziering, but turned the role down because he thought the plot was too outlandish and didn't live up to his personal standards.
He admits, "I got to tell you, I made a mistake. I turned down 'Sharknado.' They (producers) came to me, and I should've done it because it was a huge hit. It was a crazy movie.
"I read it (the script), and told everyone about it, you know, 'This is nuts, with fish flying out of the air!' But it didn't fit with me. After seeing the movie, I had a great time, and I saw the second one and it was a ball."
And Guttenberg goes on to reveal that "Sharknado" wasn't the only hit he passed on - he also turned down offers to star in movies including "Ghostbusters 2" and "Big."
He says, "I have turned down a bunch of things, but I try to forget about them because my net worth would be so high right now. I would be on a beach drinking beers right now.
"But you can't do everything. There was a period of 15 years where I would work every day of the year. I was very, very lucky. I carried every single one of the movies I was in. And they all made a lot of money. But you can't do every movie."
Meanwhile, the first "Sharknado" became a TV and social media phenomenon when it debuted in 2013, and Ian Ziering was back to break Syfy network ratings records when the sequel, "The Second One," debuted last week.