Of the 250 most commercially successful Hollywood films made in 2012, over 90% were directed by men, a new report has found.
But the study, carried out by the Centre for the Study of Women in Television and Film, found that the number of women in directing roles has risen: from 5% in 2011 to 9% last year.
The study also found that women are more likely to work as directors, writers, producers, executive producers, editors and cinematographers on independently produced documentaries than on narrative feature films.
A similar study carried out by the Sundance Institute and Women in Film revealed that, when looking at the top-grossing Hollywood films, there are more than 15 male directors for every female director.
The study's director, Stacy L Smith, said: "There has been no sustained or meaningful change across the last 11 years in the percentage of directors or producers at the Sundance Film Festival," concluding that "as commerce moves in, females move out".
Women in Film president Cathy Schulman said that although women are more successful in the independent film industry, the result of the study "highlights the work that is still to be done for women to achieve equal footing in the field."
The low percentage of comercially successful female directors is reflected by the industry's awards ceremonies. Of the current Oscar nominees, no women have been nominated for best director, while Zero Dark Thirty is the only film up for best picture which has a female director: Kathryn Bigelow, who became the first female director to win an Oscar in 2010 for The Hurt Locker.