Shared decision making (SDM) is a paradigm of patient-physician communication which aims at combining the physician s expertise and the patient s individual preferences regarding a treatment decision. Although most clinicians consider SDM the most appropriate communication style, neither a precise theoretical framework nor a convincing evaluation method has been proposed yet. Since SDM is especially indicated in situations without any clearly superior treatment alternative which is often due to the lack of reliable clinical evidence several different qualities of uncertainty have to be faced and negotiated to reach a consensual decision. These include medical considerations like valuing risks and harms of each treatment as well as questions e.g. about sense of life in view of limited lifetime or reliability of the partnership under life threatening conditions. Based on qualitative interviews with cancer patients using the Grounded Theory approach, a questionnaire has been derived addressing multiple qualities of uncertainty. The QUiCC (Qualities of Uncertainty in Chronic Conditions) has been validated in a multicenter study using multidimensional Rasch models and classical item analysis procedures providing strong evidence for its reliability and validity. Open negotiation of uncertainties will probably not result in their reduction. Even so, we feel that patients would benefit from negotiating various uncertainties with their physician. Transition of uncertainty to another state rather than its replacement with an illusive certainty can nevertheless empower the patient in his or her decision-making process.