||The aim of this study was to expand the knowledge about the specific social-emotional difficulties within Klinefelter syndrome (47, XXY) by measuring attention to social cues, emotion recognition skills, empathy and emotional arousal. 14 participants with Klinefelter syndrome (age range 16-56) and 14 control participants (age range 22-60) were included. All participants watched four video clips designed to evoke empathy, and filled out a questionnaire about their own and the main character’s emotions after each video. Furthermore, they completed an emotion recognition task consisting of 80 pictures of faces with a neutral, happy, scared or angry expression. During both tasks eye movements and fixations were measured. Electrocardiogram and skin conductance measurements were done at baseline, during the video clips and during the emotion recognition task. Participants with Klinefelter syndrome had equal emotion recognition scores compared to the control group, but empathy scores were lower for the Klinefelter group. Participants with Klinefelter spent less time fixating on eyes and more time fixating outside the face during the emotion recognition task. No group differences in overall fixation times were found during the videos, but longer fixations on eyes and mouths and shorter on objects predicted better empathy scores. Psychophysiological responses differed between groups during the empathy videos: participants with Klinefelter showed somewhat stronger skin conductance reactions than controls. The current results can contribute to the development of interventions for Klinefelter syndrome. Moreover, the results can give insight into the role of the X-chromosome in the relation between (social) attention processes and social-cognitive functioning.