This study was conducted to explore the psychologic morbidity of women recalled for diagnostic assessment during population-based mammographic screening.This study prospectively attempted to measure physical, social, and emotional well-being by the administration of a questionnaire before screening, at the time of recall; and 1 month later to women recalled and matched women with those not recalled.Of the 224 women who were recalled for further diagnostic assessment and their matches, complete follow-up was obtained on 182 pairs (81.3%). In contrast to those women not recalled, recalled women exhibited increased levels of concern at the time of recall. These levels had not decreased to the initial level after 1 month, even though breast carcinoma was not diagnosed. Similar negative short term effects also were evident in the areas of physical well-being, social functioning, and anxiety and insomnia levels, although these were not sustained.Women with normal results after mass mammographic breast screening experienced no increase in psychologic distress and a decrease in their concern regarding breast carcinoma. However, those women who were recalled to follow-up after abnormal findings experienced an increase in their level of concern regarding breast carcinoma and this concern was sustained, as determined by repeat questionnaire, 1 month after a negative result had been determined.