Academic writing is generally regarded as the most important communication medium through which people in the tertiary academic context choose to communicate their ideas. It is also well known that it is sometimes an arduous process for students to become accustomed to the requirements (the conventions and conditions) that hold for the production of appropriate written texts in this context. The initial impetus for the current study was provided by what appeared to be a significant problem that some supervisors at the University of Pretoria identified in terms of the academic writing ability of their postgraduate students. This study therefore investigates postgraduate academic writing with regard to a number of such issues, and does so within the broader confines of academic literacy. The ultimate purpose of this investigation is to discover how writing interventions may be designed that offer appropriate assistance to students who experience difficulty with their writing. The study commences with an attempt to find support for treating 'academic discourse' as a potentially productive area of academic enquiry. It therefore presents an account on the nature of a 'discourse community', and attempts to ascertain whether there are any grounds on which 'academic discourse' may be regarded as a unique type of discourse used for specific communicative functions in the tertiary academic environment. It further discusses critically some of the traditional features of academic texts. The research then proposes thirteen design principles that serve as injunctions that should be considered in the development of writing courses, and proceeds to a critical discussion of the most important approaches in the teaching and learning of writing. What is evident from this discussion is that none of the historical approaches will, on their own, enable one to design justifiable writing courses. As a result, an eclectic approach is required in order to integrate the strengths of these approaches into a strategy for writing course design that is theoretically and practically justifiable. Subsequently, the critical interpretation of the literature in the first part of the study is used in the design of a framework for writing course design in tertiary education. This framework consists of six focuses that stand in a relationship of dynamic interaction towards a description of the context in which tertiary students write. Thus, relevant aspects concerning the writer, text, reader, institutional context and one's approach to writing are all essential elements that should be carefully considered in terms of their potential influence on the eventual design of materials that will constitute a writing course. The rest of the study consists of an application of the proposed framework that addresses firstly, the perceptions of supervisors at the University about the academic literacy ability of their postgraduate students, as well as their requirements for academic writing. It then proceeds to an investigation of a specific group of students' (from the Faculty of Natural and Agricultural Sciences) perceptions about their own academic literacy ability and a determination of their perceptions and expectations of academic writing at university. Because the information that was collected (by means of questionnaires) in both cases mentioned above is mainly perceptual in nature, it was considered essential to determine the academic literacy ability of students in the study group by means of a reliable testing instrument. A written text that these same students produced was further analysed in order to establish possible writing difficulties they experienced. In addition, it was important to confirm certain findings from the supervisor questionnaire, and more specific information had to be collected on particular writing issues that could inform discipline specific writing course design (this was accomplished through focus group interviews with supervisors of the School of Agricultural and Food Sciences). A combination of all the prominent findings of the empirical work mentioned above, as well as insights gained in the literature survey, is then used to make justifiable suggestions for the design of writing course materials for students in the study group. Finally, a number of issues were identified that could not be addressed by this study and, therefore, suggestions are made for future research that may investigate these matters.