Despite evidence that breast cancer screening effectively diagnoses and treats cancer through early detection, mammography use remains low in Taiwan. We applied the health belief model (HBM) and the knowledge-attitude-behavior (KAB) model as theoretical frameworks to examine factors associated with mammography uptake among women aged 45-69 years in Taiwan. A cross-sectional survey January-July 2018 was conducted of women aged 45-69 years in five southern Taiwan health institutions. Survey questionnaires included demographics, HBM constructs, and health knowledge regarding breast cancer and screening. Multivariable logistic regression models explored the mediation effects of HBM constructs between health knowledge and mammography use. The final analytical sample included 621 women; 67 did not receive mammography and 554 received mammography. When the regression model was adjusted only for demographic factors, women with adequate health knowledge were more likely to undergo mammography (AOR = 2.321, 95%CI = 1.141-3.809); in regression models including health knowledge and HBM constructs, the likelihood effect of health knowledge declined and became insignificant (AOR = 1.711, 95%CI = 0.985-2.972), indicating potential mediation effects between health knowledge and up-to-date mammography use. Overall, based on the HBM and the KAB theoretical framework, our data support that health belief played a substantial mediating role in the association between health knowledge and mammography uptake, in particular perceived barriers and cues to action in the HBM, which were modifying factors of health beliefs. Therefore, to improve mammography uptake, it may be helpful to design educational model-based interventions through tackling those modifiable perceived barriers and enhancing the intensity of external cues to action.