BackgroundMany upper-middle-income countries (UMICs), including Malaysia, continue to face low breast cancer (BC) screening rates and patients with delayed presentation of BC. This study investigated the role of beliefs about BC and use of screening (e.g. beliefs about whether or not screening reduced the possibility of dying from BC).MethodsA nationwide cross-sectional study was conducted in which a total of 813 women (aged ≥ 40 years old) were randomly selected and surveyed using the validated Awareness and Beliefs about Cancer (ABC) measure. The association between BC screening use, sociodemographic characteristics, and negative beliefs about BC screening were analysed using stepwise Poisson regressions.ResultsSeven out of ten Malaysian women believed that BC screening was necessary only when experiencing cancer symptoms. Women > 50 years and from households with more than one car or motorcycle were 1.6 times more likely to attend a mammogram or a clinical breast examination (mammogram: Prevalence Ratio (PR) = 1.60, 95% Confidence Interval (CI) = 1.19–2.14, Clinical Breast Examination (CBE): PR = 1.61, 95% CI = 1.29–1.99). About 23% of women expected to feel anxious about attending BC screening, leading them to avoid the procedure. Women who held negative beliefs about BC screening were 37% less likely to attend a mammogram (PR = 0.63, 95% CI = 0.42–0.94) and 24% less likely to seek a CBE (PR = 0.75, 95% CI = 0.60–0.95).ConclusionsPublic health strategies or behaviour interventions targeting negative beliefs about BC screening among Malaysian women may increase uptake and reduce late presentation and advanced-stage cancer. Insights from the study suggest that women under 50 years, in the lower income group without a car or motorcycle ownership, and of Malay or Indian ethnicity (compared to Chinese-Malay) are more likely to hold beliefs inhibiting BC screening.