The present work was developed in the context of contemporary Translation Studies, in accordance with Post-Structuralist theories in the field of Social Studies. Adopting a critical view that attempts to reunite theory and practice, academy and industry, this study investigates the practice of subtitle translation - seen within the scope of audiovisual translation - based on a systemic and functional perspective. The theoretical and methodological bases are Polysystem Theory and the fundaments of Descriptive Translation Studies, which are here increased and adapted to comprehend the field of audiovisual translation. Subtitling is then studied from a large-scale context - including the institutions, professionals and proceedings involved in the subtitling of audiovisual materials - and focusing on progressively smaller units: media, technical parameters, syntactic and stylistic norms. Finally, by examining the process of translation in the area of subtitling, this study leads to reflections on the singular dimension of the translator s task - a gap in Descriptive Translation Studies and still little explored in translation theories in general - and to considerations on the possibility of combining the descriptive paradigm with research about the subjectivity intrinsic to translation.