Mammographic screening produces markedly smaller breast cancers with fewer axillary lymph nodes and more ductal carcinoma in situ. Over the past 25 years at the New England Deaconess Hospital, the mean maximum diameter of breast cancers has decreased by 10% every 5 years and is now only 2.1 cm. The median maximum diameter in the years from 1989 to 1993 is only 1.5 cm. Axillary lymph node metastases also are declining progressively. This continuing decline in mean and median maximum diameters and incidence of axillary lymph node metastases shows no signs of abating at the present time. Universal mammographic screening of appropriately aged women should be a public health goal to further this trend towards markedly earlier breast cancer detection with much higher survival and new opportunities for modified therapy.