Gurley Brown died Monday morning at New York-Presbyterian Hospital/Columbia after a brief hospitalization, the publisher said.
"Helen was one of the world's most recognized magazine editors and book authors, and a true pioneer for women in journalism -- and beyond," Hearst Chief Executive Frank Bennack said.
Gurley Brown was editor in chief of Cosmopolitan for more than three decades. She started in 1965 and was "tireless" in the job, growing the magazine in the 1980s to 300 pages -- one-third of which were lucrative advertisements, Hearst said.
Sales and advertising have since risen, making the magazine one of the top-selling women's magazines in the world, Hearst said.
Gurley Brown left the magazine in 1997 to become editor in chief of Cosmopolitan's 64 international editions. The magazine is published in 35 languages and in more than 100 countries, the corporation said.