One in nine American women will be diagnosed with breast cancer at some time in their lives. Although mammography is a proven technology for diagnosing early, curable breast cancer, most women do not obtain regular mammograms. The purpose of this study was to identify the characteristics of women who received more than one mammogram. Such information is needed to develop health education programs aimed at fostering adherence to routine mammographic screening. The data were obtained from a 1989 random telephone survey of 910 women 50-74 years of age. The survey is part of the evaluation strategy for a five-year breast screening study. Two-thirds of the respondents reported having had mammograms. Most of these women had one or two mammograms. We report two logistic regression models which describe women who had mammograms in the past year and those who had one versus two or more mammograms. The most important variable in the models was physician support. Other consistently significant variables included being willing to pay $75-$100 (although most women did not pay this amount), visiting the doctor at least annually when healthy, being a nonsmoker, and recognizing that women older than 50 are at greater risk for breast cancer. The results indicate that two-pronged educational strategies aimed at both women and their physicians are needed to increase the percentage of women who obtain regular mammograms.