The growing field of corpus linguistics has been engaged heavily in language pedagogy during the last two decades. This has encouraged researchers to look for more applications that corpora have on language teaching and learning and led to the emergence of using corpora in language testing. The aim of this article is to provide an overview of using corpus data for the purpose of vocabulary test designing. It presents some native and learner corpora which are available for item writers to use. It covers the benefits and limitations of using corpora in language testing and argues for the importance and usefulness of using native as well as learner corpora as tools for designing a vocabulary test. The article aims to illustrate how both native and learner corpora can be used in language testing in general and in the development of vocabulary tests in particular.