A conditioned taste aversion experiment tested context-switch effects on retrieval of conditioned stimulus (CS)-unconditioned stimulus (US) acquisition performance in rats. A context switch impaired performance when the target flavour was trained in a context where a different flavour underwent extinction. Conditioned taste aversion in the absence of previous extinction of the alternate flavour was not context dependent. It is suggested that the ambiguity in the meaning of the extinguished cue leads animals to pay attention to the context, so that the information learned in that context becomes context dependent.