Since their invention, numbers and differing forms of displays have grown at an almost exponential rate in the last fifty years. That type of growth is making it ever more difficult, in both the developed and developing countries, to find situations where different types of displays do not play a critical role – from our work to personal pleasure. Displays pervade our lives in aspects like entertainment, transportation, military services, industrial control as well as the portable devices which represent modern personal life. For that reason displays, and all of their innate characteristics like size and shape, have captured the attention of scientists from various fields – ranging from sociology, psychology, ergonomy to marketing and philosophy. Based on their extensive research, it is well known today that screens, more specifically their size, have an impact on evaluation, attention, and arousal of the content being watched. Guided with that exact premise this paper set a goal to investigate the effects of screen size (small (5“), medium (11,6“) and large (32“)) and visual message content (positive, neutral and negative) on electrodermal activity (more precisely - skin conductance response). The research was conducted on a sample of 36 female students from the University of Zadar, and it was found that screen size had no effect on electrodermal activity. Consequently, it was found that message content had a significant effect on electrodermal activity. More precisely, the negative message content induced reactions that were greater in intensity than the remaining two content types (positive and neutral). Differences in electrodermal activity between the remaining two content types were not found.