This paper examines the discursive construction of refugees and asylum seekers (and to a lesser extent immigrants and migrants) in a 140-million-word corpus of UK press articles published between 1996 and 2005. Taking a corpus-based approach, the data were analyzed not only as a whole, but also with regard to synchronic variation, by carrying out concordance analyses of keywords which occurred within tabloid and broad-sheet newspapers, and diachronic change, albeit mainly approached from an unusual angle, by investigating consistent collocates and frequencies of specific terms over time. The analyses point to a number of (mainly negative) categories of representation, the existence and development of nonsensical terms (e.g., illegal refugee), and media confusion and conflation of definitions of the four terms under examination. The paper concludes by critically discussing the extent to which a corpus-based methodological stance can inform critical discourse analysis.