Psychophysiological responses to imagery of self-relevant illness threats were examined for high and low extreme groups of hypervigilants and health care utilizers. Heart rate, skin conductance, and respiration were the physiological measures recorded; self-reports of perceived illness vulnerability, negative affect, image clarity, and image realness were the psychological measures obtained. Responses to neutral, exercise, and illness threat scenes were compared. Hypervigilants showed an increased heart rate response to imagery of illness scenes, whereas all other groups returned more quickly to baseline levels. The results are similar to those reported by Lang for snake phobics. They also lend some support to Horowitz's theory of intrusive imagery, in which self-relevant, anxiety provoking events tend to continuously intrude upon one's thoughts, and this intrusive imagery was reflected cardiovascularly. There could be several possible underlying mechanisms for these findings.