In recent years, increasing emphasis has been put on pragmatic competence as part of foreign language curricula. This article analyzes the devices used by learners of English as a Second Language (ESL) in order to perform the "speech act of disagreement" in their L2. Data from 27 ESL learners were gathered by means of Discourse Completion Tests and compared to baseline data from 27 native speakers of American English. It was found that non-native speakers use mitigational devices such as hedges or explanations less frequently than native speakers, but often resort to undesirable features such as the "blunt opposite" or message abandonment. Moreover, three additional features of target-like disagreement expression were identified, namely, suggestions, exclamations, and a "sandwich pattern of mitigation." The data suggest that high lexico-grammatical proficiency does not necessarily imply high pragmatic competence. The findings are discussed in light of Wolfson's Bulge Theory, and teaching implications are discussed.