The feature was released internationally this week on DVD, with additional rare footage of the foursome.
McCartney enjoyed the black-and-white film tribute to 1960s Beatlemania (search) with his wife, Heather Mills, 36.
"Heather has never seen it full-length. We have just seen bits and pieces," he said.
McCartney, 62, admitted he hadn't seen the film himself since its 1964 release.
The knighted star also was reunited with the cast and crew of the film, which showed John, Paul, George and Ringo (search) navigating a series of adventures as they prepared for a TV appearance.
"Yes, it takes me back. It's great seeing it again," McCartney said, noting that "it's very sad that George and John aren't around to see it."
Lennon was gunned down outside his New York City apartment in 1980. Harrison died of cancer in 2001.
The film was an instant success upon release, bringing the young Liverpool natives even greater fame.
The film features 12 Beatles hits, including "Can't Buy Me Love," "She Loves You" and "A Hard Day's Night."