Because few studies have addressed the intention to pursue testing for breast cancer susceptibility among women in the general population, we examined whether women due for routine mammography would want such testing and what factors might impact on their decision to pursue testing. A questionnaire was mailed to women > or =50 years of age who had undergone a screening mammogram 12 to 14 months before the study. Univariate and multivariable analyses were conducted to identify factors associated with intention to pursue genetic testing. Approximately 41% of respondents probably or definitely intended to pursue testing. In univariate analysis, the intention to undergo testing was not significantly associated with age, education, marital status, potential effects on health or life insurance, or physician recommendation. Although significant in univariate analysis, family history of breast cancer and ethnicity were not significant in multivariable analysis. In both univariate and multivariable analysis, factors significantly associated with intention to undergo testing included awareness of genetic testing, cancer worry, and insurance coverage of testing cost. Intention also was associated with the respondent wanting to know whether she possessed the susceptibility gene, even if that knowledge would not impact on options for early detection or treatment. Given the relatively high level of interest in testing among women at average risk of breast cancer, these results may help health care professionals educate and counsel women regarding the appropriate use of genetic testing as well as breast cancer risk factors.