In the survey, which included more than 5,000 researchers across 117 countries, 49 percent of women scientists reported that they had "personally experienced at least one situation" of harassment.
Nearly half of the cases took place after the MeToo movement emerged in 2017, according to the survey, which was conducted by the Ipsos polling firm on behalf of the L'Oreal Foundation.
For 65 percent of the women, the harassment had a negative impact on their careers.
Just one in five of the victims reported the harassment to their institution.
"This survey confirms that science has not been through enough of a revolution since the MeToo movement," Alexandra Palt of the L'Oreal Foundation told AFP.
The foundation, which works with UNESCO to support women scientists, called on academic and research institutions to adopt zero tolerance policies regarding harassment and make budgetary commitments to address the problem.
"There needs to be an effective and transparent internal reporting system," Palt said.
The respondents to the questionnaire worked in fields including science, technology, engineering and mathematics. They worked at more than 50 public and private institutions across the world.
A quarter of the respondents said they had been in a situation where someone was "inappropriately and repeatedly referring to me as a girl... doll, babe or chick," or otherwise insulting them.
Twenty-four percent said they had been asked "intrusive and repeated questions about my private or sex life that make me feel uncomfortable," the survey said.
A majority of the harassment took place at the start of the victims' careers.
Around half said they had avoided certain members of staff at their organizations, while one in five said they had felt unsafe at their workplace.
Nearly 65 percent of the respondents said not enough was being done to combat sexism and sexual harassment in the workplace.
Only 33 percent of scientific researchers worldwide are women, and just four percent of science Nobel Prize winners have been female, the foundation said.
"If we want to fully harness the potential of women in research, they must feel safe," Palt said.
The survey was conducted by Ipsos using the consultation method from July 26 to September 12 last year.