This thesis attempts to investigate the structure of Arabic argumentative discourse in general and 'editorials' as an argumentative text-form in particular and the problems this discourse raises for translators. This investigation includes the identification of editorials' main constituents, the types of clause relations typical of this form of argumentation and their contribution to meaning continuity of such discourse, and certain textual phenomena, i.e repetition, parallelism, thematization, paragraphing, etc., and their unequivocal significance in translation. To this effect, random samples were taken from three different Arabic newspapers, i.e Al-Ahräm, Al-Ra'y, Al-Iqatan, to show how the structure of these texts gives rise to ambiguity when translated (literally) into English. To achieve these objectives, this study uses a semantic, structural, and pragma-semio-textual approach to analyze and then translate the texts chosen, as language in this study is considered to be a form of behaviour (Halliday 1973) that cannot be studied in isolation from its social, cultural, and contextual contexts in which it is used. Our textual analyses have shown some interesting results. First, editorials have their own generic structure, and such structure is presented in specific stages. Second, editorials as well as other argumentative texts are dominated by semantic causal relations; these relations tend to have a psychological impact on text-readers and should be accounted for in translation. Third, editorials favour the cohesive type of lexical repetition not only for cohesion purposes but also for persuasive functions as well. Fourth, editorials use many parallel constructions for conviction and persuasive functions. Fifth, editorials have semantic structures and stylistic features that cause problems for the English reader. These features require attention during the process of translation. All these issues tend to reflect the nature of editorials within argumentation and their unequivocal significance within the study of discourse.