Participants took longer to judge that metaphors (e.g., an insult is a razor, memory is a warehouse) were literally false than to judge that scrambled sentences (e.g., an insult is a warehouse) were false. This result is the metaphor interference effect (MIE). It demonstrates that metaphor processing is automatic. In this experiment, we found that the magnitude of the MIE is predicted by working memory (WM) capacity, with higher WM yielding a smaller MIE. This suggests that although metaphor comprehension is automatic, the early processing of metaphors is controllable by executive mechanisms. We relate our results to Kintsch's (2000, 2001) predication model. Specifically, we suggest that mechanisms of WM influence metaphor processing by affecting the effectiveness of the construction-integration process that identifies common properties between topics and vehicles. WM also influences the speed with which meanings are identified as literal or figurative.