Mark Hamill said fans who saw the first 'Star Wars' film thought it was a joke.
The 65-year-old actor, who starred as Jedi Knight Luke Skywalker in the three original sci-fi films, said fans laughed at the cinematic debut of 'A New Hope' back in 1977.
Mark told The Hollywood Reporter "At the end of the trailer it said: 'a billion light years in the making. And it's coming to your galaxy this summer.' Somebody in the balcony yelled out: 'yeah and it's coming to the Late Show two weeks after that'."
The actor, who was at the screening with his now-late co-star Carrie Fisher, who played Princess Leia, said they both giggled with the crowd but also said they were horrified.
Mark has recently returned to the 'Star Wars' franchise for the 2015 'The Force Awakens' and will be starring in the upcoming 'The Last Jedi'.
However the actor has said he has one regret about the 2015 film which is he wishes his character came to the rescue of Princess Leia after the death of Han Solo, played by Harrison Ford.
Speaking to website www.fandango.com, he admitted: "When I was reading it, I thought if Leia is trying to mentally contact me and she is unsuccessful, she'll rush to his [Han's] aid and get into some dire situation, and that's when I show up.
"I save her life, and then we rush to Han, and then we are in the same position that Rey and Finn and Chewie are -- too late to save him, but witnesses."
Meanwhile, Mark has said that his character could turn to the dark side in new movie 'The Last Jedi'.
Speaking at the Star Wars Celebration in Florida over the weekend, he teased: "It's possible, anything's possible."
Mark also admitted that he doesn't agree with "everything" that has been decided for his character by producer Rian Johnson in the forthcoming film.