Background: Female BRCA mutation carriers have an increased lifetime risk for breast and ovarian cancer compared to the general population. Women who carry this mutation have several options to deal with their cancer risk, such as risk-reducing surgeries or intensified breast cancer screening. Previous research has shown that preferences in this scenario are highly dependent on affected women's personalities and value systems. To support these women in the decision-making process, a structured decision support consisting of decision coaching combined with a decision aid might be helpful. Methods/design: A randomized controlled trial will be conducted in order to compare usual care with structured decision support alongside usual care. The decision support program entails nurse-led decision coaching as well as an evidence-based patient decision aid. Nurses are qualified by a 4-day training program in informed decisionmaking and decision coaching. Six centers for Familial Breast and Ovarian Cancer in Germany will be included in the study, with a planned sample size of 398 women. The primary outcome is the congruence between the preferred and the actual played role in the decision-making process as measured by the Control Preferences Scale. It is hypothesized that the structured decision support will enable women to play the preferred role in the decision-making process. Secondary outcomes include the knowledge and attitudes about preventive options, decisional conflict, depression and anxiety, coping self-efficacy, impact of event, and self-concept. A process evaluation will accompany the study. Discussion: The EDCP-BRCA study is the first study to implement and evaluate decision coaching combined with a decision aid for healthy BRCA mutation carriers worldwide. Trial registration {2a}: DRKS-ID: DRKS00015527. Registered 30 October 2019.