Garai, who plays Bel in The Hour, explained that there were a lot of problems during the era.
"I find a lot of the 1950s nostalgia, especially in terms of women, very dubious," she told The Daily Telegraph. "This is a very morally conservative time, not a great time for women.
"Particularly when people say it was a time of optimism. Well, Britain was post-war, rationing only ended two years before our show is set - it was a bomb site. Britain was still desperately trying to cling on to its empire. It was a dark time, I think. So I hope that The Hour explores that kind of ambiguity because I think it's easily overlooked."
Garai, who described herself as a feminist, also revealed that she was interested in the lives of women during the 1950s.
"What I found fascinating was that it was a time when women were entering the workplace, but not married women," she said. "So your career was a choice and those women chose their career over partnership, companionship, children. It was a massive amount of sacrifice."
She added: "I have always been interested in gender politics, so I'm not that keen on doing things that don't represent a truth about women."
The Hour begins tonight at 9pm on BBC Two.
> 'The Hour': Dominic West, Romola Garai interview
> Ben Whishaw teases 'The Hour' role
> 'The Hour': Episode one in pictures
Watch a trailer for The Hour below: