Researchers surveyed more than 6,000 people at six public attractions in four major cities, observing whether they washed their hands after using the restroom. Ninety percent of the women observed washed their hands, compared to 75-percent of men.
People were observed at venues in Atlanta, Chicago, New York and San Francisco.
In a telephone survey of more than 1,000 American adults, 97-percent of women and 96-percent of men say they always or usually wash their hands after using a public restroom.
Among those observed, fans at Atlanta's Turner Field had the worst hand-hygiene habits - one-fourth did not wash their hands after using the facilities. The greatest gender disparity observed between women and men hand-washers was in New York's Penn Station with 92-percent of the women washing their hands, compared to only 64-percent of the men.
Those traveling through San Francisco's Ferry Terminal Farmers Market came out on top with 88-percent washing their hands.
