The subject of the investigation is theoretical writings on acting in Spain dating back to the late eighteenth century, with developments during the nineteenth century, when Spanish treatises became widespread and interacted with the Italian, French and German theatrical milieu. The article explores more in detail the first Spanish treatises and manuals for acting, investigating its sources of inspiration and finally focusing on the first illustrated treatise, the “Ensayo sobre el origen y naturaleza de las pasiones, del gesto y de la acción teatral” (1800) by Fermín Eduardo Zeglirscosac.