OBJECTIVE: Although shared decision making (SDM) has become increasingly important in bioethical discussions and clinical practice, it is not clear in which treatment situations SDM is suitable. We address this question by investigating social norms on the appropriateness of SDM in different situations. METHODS: We conducted qualitative expert interviews with patients, general practitioners, and health administration and research professionals. RESULTS: SDM was considered to be most important in severe illness and chronic condition. Furthermore, SDM was indicated to be required if there is more than one therapeutic option, especially if it is not clear which option is best. Interviewees classified end-of-life decisions and decisions about prevention as those that primarily should be made by informed patients. On the other hand a paternalistic decision was considered most appropriate in emergency situations and when the patient does not want to participate in decision making. CONCLUSION: This study demonstrates that multiple situational factors and their interactions must be considered regarding the scope of SDM in medical consultation. PRACTICE IMPLICATIONS: Research addressing this question will help physicians adjust their consultation style and allow implementations of SDM and decision aids to be tailored more appropriately to complex treatment situations.