Determining the indication for carotid endarterectomy in a given patient with a totally symptom-free internal carotid artery stenosis depends on objectively assessing the risk of non-operative versus operative treatment, as well as on the patient's attitude towards immediate versus long-term risk. In order to study patients' attitudes and preferences, four groups of subjects were asked to complete two questionnaires: the first examined people's perceived deterioration in their quality of life if they sustained a stroke of a defined severity. The second checked the attitude towards risk of operative versus non-operative treatment at different levels of an expected annual stroke rate without surgery. This preliminary study showed the feasibility of studying these subjective elements, and also pointed to problem areas in this type of research. The existence of individual as well as group differences in patients' values and preferences should be considered in the decision-making process.