To assess how women regard having had a false positive mammogram screening exam, and the influence that this had on their quality of life, 126 such women were interviewed. Their responses were compared to those of 152 women randomly selected among screenees with a negative exam. Eighteen months after the screening the reported prevalence of anxiety about breast cancer was 29% among women with a false positive and 13% among women with a negative screening mammogram (P = 0.001). Of 30 women biopsied, 8 (27%) had pain in the breast and 10 (33%) had reduced sexual sensitivity. A false positive mammogram was described by 7 (5%) of the women as the worst thing they ever had experienced. However, most women with a false positive result regarded this experience, in retrospect, as but one of many minor stressful experiences creating a temporary decrease in quality of life. They report the same quality of life today as women with negative screening results and 98% would attend another screening. Even so, false positive results are a matter of concern, and efforts should be made to minimise this cost whenever a screening programme is conducted.