This thesis is a study of subtitling for the deaf and hard-of-hearing (SDH) with special focus on the Portuguese context. On the one hand, it accounts for a descriptive analysis of SDH in various European countries with the aim of arriving at the norms that govern present practices and that may be found in the form of guidelines and / or in actual subtitled products. On the other hand, it is the result of an action research project that aimed at contributing towards the improvement of SDH practices in Portugal. These two lines of research are brought together in the proposal of a set of guidelines for the provision of SDH on Portuguese television. This research positions itself within the theoretical framework of Translation Studies (TS) by taking a descriptive approach to its subject. Nonetheless, it takes a step beyond to seek reasons and to propose change rather than to simply describe objects and actions. Given its topic and methodological approach, this research also drank from other fields of knowledge such as deaf studies, sociology, linguistics and cinema studies, among others. In this context, SDH is addressed as a service to deaf and hard-of-hearing viewers, thus implying a functional approach to all that it entails. In order to arrive at an encompassing understanding of the subject, in the body of this work, we may find a summary of the history of SDH, as well as an overview of the overriding and specific issues that characterize this type of subtitling. Following this, the Portuguese situation is made known through the account of five case studies that were carried out in the course of 2002 and 2003. In response to the needs and requirements of Portuguese deaf and hard-of-hearing viewers, the proposed set of guidelines is based on the special concern for adequacy and readability and is envisaged as a useful tool for students and practitioners of SDH. [Based on abstract in journal]