Purpose: The study was done to examine the effects of cognition-behavior integrated breast cancer prevention education, in which a breast model with interchangeable nodules was utilized, on the self-competency of nursing students in performing breast cancer education. Methods: A nonequivalent control group non-synchronized design was used. A traditional lecture intervention was provided for 49 3rd year college of nursing students (control group) while the integrated breast cancer prevention education was given to 47 3rd year students in the same college one year later (experimental group). The integrated breast cancer prevention education was developed by the research team to strengthen the competency of cognitive and behavioral components in education on breast cancer. Results: Effects of the intervention were found to be significant through all study variables: knowledge about breast cancer (t=7.79, p <.001), breast cancer risk awareness (t=2.05, p <.05), self-competency of breast self-exam (t=8.27, p <.001), and intention to teach breast self-exam (t=3.87, p <.001). Conclusion: The integrated breast cancer prevention education was useful to improve not only knowledge about breast cancer but competency in performing breast examination for nursing students who acquired technical skills from various simulation nodules. As the program helped the students to be prepared as confident educators, future application of the module is recommended for academic curricula.