Arts experts are commonly skeptical of applying scientific methods to aesthetic experiencing, which remains a field of study predominantly for the humanities. Laboratory research has, however, indicated that artworks may elicit emotional and physiological responses. Yet, this line of aesthetics research has previously suffered from insufficient external validity. We, therefore, conducted a study in which aesthetic perception was monitored in a fine art museum, unrestricting to the viewers' freedom of aesthetic choice. Visitors were invited to wear electronic gloves through which their locomotion, heart rate and skin conductance were continuously recorded. Emotional and aesthetic responses to selected works of an exhibition were assessed using a customized questionnaire. In a sample of 373 adult participants, we found that physiological responses during perception of an artwork were significantly related to aesthetic-emotional experiencing. The dimensions "Aesthetic Quality," "Surprise/Humor," "Dominance," and "Curatorial Quality" were associated with cardiac measures (heart rate variability, heart rate level) and skin conductance variability. This is the first evidence that aesthetics can be statistically grounded in viewers' physiology in an ecologically valid environment-the art gallery- enhancing our understanding of the effects of artworks and their curatorial staging.