Background: Given the history of vulnerability of women of childbearing age to medical treatments that have caused injury, for example, diethylstilbestrol (DES) and thalidomide, it is surprising that, to date, little research has directly examined attitudes of the general public regarding the vulnerability of women when they participate in biomedical research studies. Methods: We asked three questions about beliefs of women as biomedical research subjects of 623 white, 353 black, and 157 Hispanic people in four U.S. cities: (1) Do you believe that women are more likely to be "taken advantage of" when they become subjects in a medical research project as compared to men? (2) Do you believe that women of childbearing age (15-45-year-olds) should become study participants in medical research projects? and, if the response was no or don't know/not sure, (3) Would you still say no or don't know/not sure to question 2 even if it meant that we would not know anything about the health and medical treatments for women aged 15-45 years? Results: Overall, women were 60% more likely than men to state that women were more likely than men to be "taken advantage of," even when controlling for potential confounders, and both black and Hispanic participants were much more likely than white participants to state that this was the case. The majority of respondents (57.4%) said that women of childbearing age should not be research subjects; among women, both black and Hispanic people were less likely than white people to change their minds when prompted that this might mean that "nothing would be known about the health and medical treatments for women aged 15-45 years." Conclusions: A substantial proportion of the participants reported knowledge of historical events, and this knowledge was related, particularly in black participants, to attitudes toward vulnerability of women as biomedical research subjects.