['To bring further understanding to the relationship between hormonal therapy (HT) and breast arterial calcification (BAC).', 'Of women arriving for breast cancer screening mammography, 1995 consented to complete a survey and have their mammograms analyzed for the presence of BAC. The survey assessed HT use and major risk factors for CAD.', 'Of the 1919 women with complete data, there were 268 with BAC (14%). When categorized into three age groups, BAC was present in 40.7% of the women > or =65, 10.9% of those 55-64 and 3.0% of those <55. The > or =65 year-old group showed a nearly 50%-point lower prevalence of BAC among HT users compared with women who were not on HT (25.8% versus 74.2%, respectively, p=0.006). With age included as a continuous variable, past use of HT was significantly associated with a lower prevalence of BAC (p<0.03), while the presence of diabetes or a history of stroke were significantly associated with a higher prevalence of BAC (p<0.002).'] Is hormonal therapy associated with a lower prevalence of breast arterial calcification on mammography?