The movies that made the most money in 2018 - such as Black Panther, Avengers: Infinity War, Incredibles 2 - were all directed by men.
That's the norm when it comes to Hollywood's biggest films, according to US campaign group, Time's Up.
They've shared figures which reveal only 4% of the biggest earning films from the past decade have been directed by women.
And now they're calling on Hollywood studios and stars to change that.
Time's Up has launched the #4percentchallenge, and stars Tessa Thompson, Brie Larson and Bryce Dallas Howard are among the names to lend their support.
'Women are hired on experience and men are hired on potential'
Time's Up's campaign to draw attention to this inequality has been welcomed by rising female film talent here in the UK.
"Four percent is a pretty depressing figure, but things like this challenge are absolutely necessary," British director Georgia Parris told Radio 1 Newsbeat.
She premiered her first full-length film, Mari, at the BFI Film Festival.
"It's that age-old problem that women are hired on experience and men are hired on potential.
"So if we're not being given the opportunities to gain that experience then how is the problem ever going to change?"
But she says the success of 2017's Wonder Woman is an early sign that things are starting to change.
"I think there's a sense that women tend to direct sensitive, female-based issue films but these are the ones that tend to cost less money," she adds.
"But you look at something like Wonder Woman and that's done hugely well.
"We're starting to see those snippets of women being trusted with bigger budgets."
'Raw, truthful depiction of women'
Movements like the #4percentchallenge are inspiring confidence in future movie-makers, such as film student and aspiring director Beatrice Sutcliffe.
"We're living in the dark ages when it comes to representation in film and the films that are being made," Beatrice tells Newsbeat.
"We need to try and give women more of a spotlight because it's so unequal."
"I'm passionate about breaking through that."
Alongside a more "truthful depiction of women," Beatrice says she wants to see an end to male-directed films using women's bodies as a punchline.
"I want to see a film where a woman actually has her period and it doesn't stop her," she says.
"That's raw, that's real, that's what women are going through. At the end of the day, when a woman is having a period in a film, it tends to be as a comical gag.
"A female director can bring that raw, truthful depiction of women."
Aim is to help 'all groups thrive'
Time's Up claims movies directed by women are more inclusive for girls and women, female characters over 40 and racial and ethnic groups.
"Women directors also hire other women in key behind-the-camera roles," it says in a statement.
"The aim is to humanize production processes so that all groups can thrive at work in safe contexts."
They're asking actors to commit to working with a female director in the next 18 months.
Already, a number of well known actors have signed up to support the campaign.
A list of supporters on the Time's Up's website includes Amy Schumer, Armie Hammer, Jordan Peele, Jussie Smollett, Reese Witherspoon and Zazie Beetz - among many others.
Efforts have been made in the UK to raise female representation, such as 38% of the films screened at the 2018 BFI Film Festival (a major London event) being directed by women.
Big studios are starting to make changes too
Film studios such as JJ Abrams' Bad Robot, Universal and Disney have also signed up to support the #4percentchallenge, and Disney CEO Bob Iger claims his company is already making big steps toward better female representation in the director's chair.
Many have contacted us about accepting the 4% challenge, but I’m proud to say 40% of @DisneyStudios’ upcoming movie slate is being directed by women and we are striving for more!— Robert Iger (@RobertIger) January 31, 2019
Among comments of support for Disney's stance, some say they just want studios to "hire the best person for the job," regardless of gender.
But Georgia says storytellers need to represent society more than this viewpoint suggests.
"Men can direct beautifully - sensitive and feminine stories as well. But at the end of the day, if we're only ever given one viewpoint, a male viewpoint, that is not representative of the world that we live in," she says.
"We just have to have a variation of women telling those stories as well to get a more equal balance."
Disney's next big Marvel movie, Captain Marvel, has two directors - one woman, one man (Anna Boden and Ryan Fleck).
"With Captain Marvel coming, I think it's a really important time for female directors, especially those who want to work in the big mainstream Hollywood stuff to come forward and really fight to do that work," says Beatrice.
Many of Disney's biggest franchise films currently in production - such as Avengers: Endgame, Aladdin, Toy Story 4, Star Wars IX and The Lion King are all directed by men.
However, other Disney films such as Marvel films The Eternals and Black Widow and the Mulan remake all have female directors.