OBJECTIVES: The anti-vaccination movement is prevalent in today's media with claims which continue to create feelings of fear and trepidation in the minds of many parents. The C.A.S.E. Approach (Corroboration, About Me, Science, Explain/Advise) is a method ofcommunication to be used in formulating meaningful, rapid responses to parents hesitant to vaccinating their children. This DNP project assessed the effects of a C.A.S.E. Approach learning module on family nurse practitioner (FNP) students' perceived levels of knowledge and self-efficacy regarding vaccination discussion with vaccine hesitant parents (VHPs). METHODS: This DNP project used a pretest-posttest design to measure the effects of the C.A.S.E. Approach training intervention on both knowledge and self-efficacy levels of FNP students. Fourteen students participated in this study. Each took the 20-question pretest C.A.S.E. Approach Questionnaire, then participated in the C.A.S.E. Approach learning module,and finished by repeating the questionnaire as a posttest following the intervention. The questionnaire was designed using four-item Likert questions scored 1 (strongly disagree) to 4(strongly agree), wherein higher scores reflected better understanding and self-efficacy in the C.A.S.E. Approach. Students were recruited via an online classroom format within a nursing course offered at the University of Arizona: Nursing 612, Introduction to Pediatrics. All testing and module information was accessed online and questionnaire responses were stored at Qualtrics.com, also online. RESULTS: Students' posttest scores following the intervention of the C.A.S.E. Approach learning module were significantly higher than pretest scores. Perceived knowledge (p< 0.001)of the C.A.S.E. Approach increased more significantly than did perceived self-efficacy (p =0.001) of the C.A.S.E. Approach following the module. Mean test scores increased on average 14.29 points in perceived knowledge of the C.A.S.E. Approach following the module, and 7.93 points for perceived self-efficacy following the module. CONCLUSION: Key findings included an observed increase in participating students' perceived knowledge regarding the C.A.S.E. Approach as well as an observed increase inparticipating students' perceived self-efficacy in using the C.A.S.E. Approach. There was strong statistical evidence (p≤0.05) to suggest the learning module increased student knowledge andself-efficacy regarding vaccine discussion.