This study identified barriers and facilitators of repeat participation in mammography and breast physical examination among women ages 50 years and over. Telephone interviews were conducted with 910 women in this age group. Forty percent of respondents had never had a mammogram. Only 38% had had one in the past 12 months. Of women who had a prior mammogram, 43% had had only one. Only 60% of women had had a breast exam in the past 12 months. A physician recommendation was the single best predictor of adherence to mammography. However, only 60% of women reported that their physicians had ever recommended mammography. Several other barriers to mammography were revealed, including anxiety, embarrassment, and concerns about cost and radiation. Both a family history of breast cancer and heightened perceived vulnerability to breast cancer were associated positively with repeat mammography participation; anxiety about screening reduced the likelihood of this outcome. These findings suggest that physicians can play a powerful role in motivating women to participate in initial and subsequent breast cancer screening. Reassurance may reduce women's anxiety and embarrassment and increase utilization further.