Canadian guidelines recommend shared decision making for women less than 50 years old who are considering breast cancer screening. Nurses can support women in making these decisions. This single case pre-/post-test study measured change in decisional conflict after decision support for a woman less than 50 years old considering whether or not to initiate mammography screening. At baseline, a 44-year-old female at average risk of breast cancer was experiencing decisional conflict. She scored 1 out of 4 on the SURE test indicating feeling uninformed, unclear values, and inadequate support. After receiving decision coaching with a breast cancer screening decision aid by a nurse trained in decision coaching, she scored 4 on the SURE test indicating no decisional conflict. She reached an informed decision consistent with her values about mammography screening. Providing decisional support improved her knowledge, reduced her decisional conflict, and enhanced her confidence in making an informed decision that was consistent with her values.