In this brief article, I discuss the relationship between language testing and the other sub-disciplines of applied linguistics and also the relationship, as I see it, between testing and assessment. The article starts with a brief exploration of the term ‘applied linguistics’ and then goes on to discuss the role of language testing within this discipline, the relationship between testing and teaching, and the relationship between testing and assessment. The second part of the article mentions some areas of current concern to testers and discusses in more detail recent advances in the areas of performance testing, alternative assessment, and computer assessment. One of my aims in this article is to argue that the skills involved in language testing are necessary not only for those constructing all kinds of language proficiency assessments, but also for those other applied linguists who use tests or other elicitation techniques to help them gather language data for research.