Cognitive Linguistics has seen a recent interest in expressions in which several metonymies interact (Nerlich & Clarke 2001, Geeraerts 2002, Barcelona 2003). While these contributions have aimed at a theoretical description of isolated examples, this paper offers a corpus-based approach to chained metonymies. Consider the contrast in examples (1) and (2). (1) Keep your eye on the paper! (2) Keep your eye on the real issue! Example (1) means 'Keep watching!" whereas example (2) means 'Keep paying attention!', with no reference to visual perception. This could lead the researcher to posit two different metonymies, namely EYE FOR WATCHING and EYE FOR ATTENTION. In this paper I argue for a different solution, namely chained metonymies. In example (2) the metonymy EYE FOR WATCHING is extended by a second metonymy WATCHING FOR ATTENTION. The question what types of metonymies interact can only be settled through investigation of authentic data. I draw three conclusions from this study. First, metonymic expressions are organized in patterns - these patterns trigger specific metonymies. Second, lexical items are associated with a limited number of base metonymies, which form the basis for extending metonymies. Third, base metonymies and extending metonymies employ different kinds of conceptual relations. (Martin Hilpert)