This paper describes how legal drafters use metalanguage in order to avoid ambiguities in the interpretation of their texts. Firstly, the author will refer to the various strategies of statutory construction which are employed in England and Wales, and in Spain. Secondly, he will analyse the metalinguistic expressions which are most usually found in contracts (e.g. with the aim of defining the key terms of the agreement). Finally, the author will offer a brief introduction to some of the main difficulties which metalanguage in legal texts may pose for Translation students.