This paper briefly discusses the way in which the training of interpreters is organised in various countries. Then, the authors suggest a methodology for interpreting training based on the analysis of the differences and similarities between translation and interpreting. On the one hand, the prospective interpreter needs to have a knowledge of the main principles of translation. On the other hand, s/he has to be aware of the differences between written and oral communication. This article analyses the main differences which have to be considered for the teaching of interpreting, such as the decoding process, the relation between the speaker and the interpreter, the paralinguistic information, the immediacy or the greater scope for 'freedom' before the original.