This cross-sectional survey was carried out to assess the decisional balance of Korean women toward mammography screening. A sample of 1, 903 naturally postmenopausal women was selected from the community-based social groups in town or city hall auxiliaries in seven metropolitan areas and six provinces in Korea. The classification of women according to the stage of adoption of mammography was 54.9% in pre-contemplation, 31.9% in contemplation, 7.8% in action, and 5.5% in maintenance. The mean differences of pros, cons, and the decisional balance by the stage of mammography adoption were statistically significant. There were significant mean differences between the stages of adoption according to a woman's experience with and intention for mammography and the pros score, the cons score, and the decisional balance score. Results provide the empirical evidence for the Transtheoretical model. An association between stages of mammography adoption and decisional balance exists.