Due to the increasing amount of automation in vehicles the role of the driver changes from having an active part in the driving of the vehicle to a reactive monitoring task. Since there is currently no method to measure subjective comfort or discomfort we developed a 14-item scale to measure the discomfort of a driver. Research suggests that it is easier for users to sense the lack of comfort and because of this we used experienced discomfort as an indicator for the absence of comfort. The questionnaire was applied in an experimental driving simulator study and proved to have a high internal consistency (r = .91). Results suggest that this questionnaire is a useful tool for assessing discomfort in automated HMI. This first version is focused on, but not limited to, automation and advanced driver assistance systems in vehicles.