Few studies have examined the influence of perceived risk on breast screening behaviors among women with an increased familial breast cancer risk. This study included 1019 women aged 20-71 years from the Ontario site of the Breast Cancer Family Registry who had at least one first-degree relative diagnosed with breast and/or ovarian cancer. Information was obtained from a self-administered questionnaire completed at the time of recruitment and a follow-up telephone questionnaire. The associations between breast screening behaviors and perceived risk of developing breast cancer, measured on both a numerical and Likert-type verbal scale, were estimated using logistic regression analyses. Women who rated their risk of developing breast cancer as greater than 50% compared with less than 50% were significantly more likely to have a screening mammogram within the last 12 months (odds ratio: 1.91; 95% confidence interval: 1.15-3.16). Women were significantly more likely to have a screening mammogram (odds ratio: 1.82; 95% confidence interval: 1.17-2.81) in the past 12 months if they rated their risk as above or much above average compared with same as average or below. These findings may inform educational messages for improving risk communication of women at elevated familial breast cancer risk.