['Patient simulators incorporate a range of technical features. An understanding of which features are most valuable and which may be less so is important for simulator design and utilization. In this study, we attempted to answer the question of whether or not certain simulator features are perceived by learners as more useful than others in achieving specified educational objectives.', 'The subjects were third and fourth year medical students participating in an Emergency Medicine Simulation Workshop (n = 97). Following the Workshop, subjects rated each of 13 simulator features on a 5-point scale from distracting to extremely useful in achieving specified educational objectives; and then identified the most and least useful features.', 'There were significant differences between the scores of the most highly rated features (vital sign display, interactive voice, chest rise, and palpable pulse), and those of the features with the lowest ratings (abnormal breath sounds, prerecorded voice, IV arm, and heart tones) (4.75 vs. 3.93, P < 0.0001). Three features (heart tones, abnormal breath sounds, and prerecorded voice) were rated by more than one third of the students as distracting, not useful, or uncertain if useful. On the ranking scale, highly rated features tended to be identified as most useful, and those with the lowest ratings were more often ranked as least useful. There was a statistically significant (P < 0.0001) correlation between rating and rankings.'] Does absolute and relative value of patient simulator feature as perceived by medical undergraduates?