BBC medical drama Casualty has produced more stars than any other soap or drama, according to the Radio Times.
Kate Winslet appeared in Casualty in 1993 - four years before Titanic
Kate Winslet, Minnie Driver and The Lord of the Rings actor Orlando Bloom all had parts in the long-running drama before making it big in Hollywood.
Coronation Street, The Bill, Brookside and EastEnders have also produced big-name stars.
The dramas were rated by the number of successful actors, with top marks going to those with global film or TV fame.
Oscar winners Brenda Fricker and Ben Kingsley appeared in Casualty and Coronation Street respectively while Hollywood stars Keira Knightly and Sean Bean had parts in The Bill.
Winslet told the Radio Times her 1993 appearance in Casualty - four years before filming the Oscar-winning Titanic - had been important.
The Bill - Keira Knightly (above), Sean Bean, Paul Bettany, John Hannah, Alex Kingston
Casualty- Kate Winslet, Orlando Bloom, Minnie Driver, Christopher Eccleston, Parminder Nagra, Jonny Lee Miller, Helen Baxendale, Brenda Fricker
She said: "In England, it almost seems to be part of a jobbing actor's training.
"As far as I was concerned it was a great episode, a great part.
"Appearing in Casualty taught me a big lesson in how to be natural in front of the camera."
Mal Young, the BBC's controller of continuing drama series, also started his career in front of the camera as an extra, then went on to work as a producer on Brookside.
He said the intensity of working to a soap schedule was a steep learning curve for actors.
Coronation Street - Ben Kingsley (above left), Davy Jones, Kevin Whately, Gordon Kaye, Joanne Whalley, Martin Shaw
Brookside - Anna Friel, Sue Johnstone, John McArdle, Claire Sweeny, Nicola Stephenson, Gillian Kearney
EastEnders - Martine McCutcheon, Michelle Collins, Nick Berry, Michael French, Amanda Holden
But he warned that the trend of writing drama specifically for a soap star - such as Ross Kemp, who played Grant Mitchell in EastEnders - may have gone too far.
He said: "People say, 'Look how popular Martin Kemp (Steve Owen, EastEnders) is, let's give him a deal and put him in everything and the viewers will love him'.
"But you've got to think, 'Are they working because of who they are, or because of the show they're in?
"I think we sometimes build up their expectations falsely. Actors come to me and say, 'I've just had a big storyline, it's been a great six months, can I have my own series? Then I'm off to Hollywood'."
Sylvia Young, founder of the Sylvia Young Theatre School, which has provided many future EastEnders - from Danniella Westbrook to Dean Gaffney - said the UK was a celebrity-hungry nation.
"Soap has become a stepping stone to other things, because you do become a celebrity overnight," she told the Radio Times.
"Generally, if you're a good actress and have the looks and talent, there are great opportunities."
Sean Bean appeared in the fourth ever episode of The Bill in 1984
But as well as making stars out of the cast, soaps have acted as a springboard for writers.
Paul Abbott, who wrote the critically-acclaimed State of Play and Shameless, got an early writing job on Coronation Street.
He said: "It was the sharp end. The scripts had to be in the post by Friday, no excuses."
Kay Mellor, who went on to write Fat Friends, also wrote for Coronation Street and Anthony Minghella was a script writer on EastEnders prior to scooping Oscar success with The English Patient.