This study applied the self-regulation model to examine cognitive and emotional predictors of screening in unaffected women with a strong family history of breast cancer. 748 unaffected female members of an Australian registry of multiple-case breast cancer families formed the sample. Participants completed a baseline psychosocial questionnaire and a screening questionnaire 3 years later. Multinomial logistic regression was employed to determine predictors of under- and over-screening according to national guidelines. At follow-up 16% of women under-screened and 10% over-screened with mammography; 55% under-screened with clinical breast examination (CBE); and 9% over-screened with breast self-examination (BSE). Of the women found screening according to guidelines for mammography 72% reported ever having received specific recommendations for mammography screening from a health professional. Compared to appropriate screeners, under-screeners on mammography were less likely to have received a screening recommendation (as were under-screeners on CBE), were younger and reported lower perceived breast cancer risk, but were at higher relative risk (RR) of breast cancer and were more likely to report elevated depression. Over-screeners on mammography were more likely to be younger and have a lower RR of breast cancer. Over-screeners on BSE reported elevated cancer-specific anxiety, were less likely to be university educated and more likely to have received a recommendation for BSE. Under- and over-screening is common in women with a strong family history of breast cancer. Evaluation of interventions targeting perceived risk of breast cancer, anxiety and depression are needed to ensure women obtain accurate advice from relevant specialists and enact screening recommendations.