In the Scandinavian countries, in contrast, around half of the women reported physical or sexual violence, which researchers at the European Union Agency for Fundamental Rights said could have several explanations.
Researcher Joanna Goodey told the TT news agency that the proportion of women working outside the home, the country's alcohol culture, as well as whether women report incidents or not could all impact on the figures.
"In some countries it can be less acceptable to talk about these things," Goodey said.
Agency head Morten Kjaerum said that the more gender equal countries had seen rapid changes in the relationship between men and women.
"There is a certain stress level created when gender roles change and old patterns are challenged," Kjaerum said. "I think that's a factor we should also consider."
Across the union, the report found that 22 percent of women surveyed said they had been assaulted by a partner, but 67 percent said they did not report the incident to the police.
"What emerges is a picture of extensive abuse that affects many women’s lives, but is systematically under-reported to the authorities," Kjaerum noted in the summary of the report, which was written after interviews with 42,000 women across the union.
In Sweden, 81 percent of women said they had been harassed at some point after the age of 15 - compared to the EU average of 55 percent. After Sweden, which had the highest rate, Denmark, France, the Netherland and Finland all saw rates above 70 percent. The EU member state with the lowest rate - 24 percent - was Bulgaria.
The culture of addressing and speaking about assault, harassment and rape of women may vary extensively across the union countries, and as such skew survey results, the researchers warned. They referenced a Eurobarometer survey from 2010 that found that Bulgaria had much lower rates of physical and sexual violence against women than Sweden did.
"Either overall rates of domestic violence are much lower in Bulgaria than in Sweden; or the fact that people in Bulgaria hear considerably less than people in Sweden from family members and colleagues about domestic violence(...) is an indication that the matter is considered to be private," the report noted.
"In this regard, it could be suggested that in Bulgaria, for example, the subject of violence against women could be considered as something you do not talk about in certain settings and with certain people – including an interviewer who has just entered your home to conduct a survey."