Legal texts place particular demands on the reader owing to the institutionalized communication situation, their abstract content and language, and the indirect connection of the utterances with the extralinguistic and extralegal world. Most legal translators are not legal experts. Therefore, accessing the meaning of legal argumentation represents a major challenge, specially as legal translators mainly have to comprehend and translate texts issuing from a foreign legal system with its own legal language and terminology. With the aim of explaining the particular difficulties of legal text understanding and translation, this article takes up some general theoretical approaches of mental organization of word knowledge and speech comprehension developed in cognitive linguistics and psycholinguistics. These general models are adapted to the understanding of legal text comprehension, focusing on the mental representation of highly abstract legal language and legal arguing. On that basis, a cognitive-translational model of legal text understanding is developed. Finally the use of the model is discussed as a theoretical contribution to legal translator training and with regard to the particular position of the legal translator within the communication process.