We introduce a novel and simple method for assessing audiences’ emotional responses to audiovisuals (e.g. films). Viewers (N = 21) watched movies and TV commercials from different genres while wearing photoplethysmography (PPG) optic sensors on their wrists. Heart rate variability (HRV) synchrony was observed among the audience. Based on this between-subject synchrony measure, we identified emotionally arousing segments from the materials. New participants (N = 24; N = 16) were then invited to watch these identified segments along with some randomly selected segments as control; they reported that the former was more engaging (effect size w = .67; w = .5). This finding was confirmed in an online study with a larger cohort (N = 300). While some specific effects varied depending on movie genre or gender, HRV-based editing generally performed better than the control. These findings suggest that HRV synchrony can be used as a new tool for audience psychology, and potentially also for automatically creating short trailers out of movies in a principled manner while taking into account the human perspective.