<p>Amid rising global polarization, finding ways to disagree constructively is vital. This paper examines whether the medium of disagreement—spoken or written—shapes conversation outcomes. A series of randomized experiments (<i>N</i> = 1,576 conversation partners who had 1,842 conversations and 1,432 observers of those conversations) suggests that spoken conversations with a disagreeing counterpart lead to greater understanding, lower conflict, more favorable impressions of one’s counterpart, and greater attitude alignment than written ones. Speech also fosters more conversational receptiveness—cues in language that signal openness to opposing viewpoints—which partly mediates the effects of medium on these constructive disagreement outcomes. The conversation medium further moderates the association between language and outcomes: receptiveness is a stronger predictor of constructive disagreement in writing than in speech, suggesting people use less receptive language in the very medium in which it may be most effective (i.e., the written medium). A final study suggests that people may misjudge the effects of medium, wrongly believing spoken (versus written) disagreement will be less constructive and preferring to write to disagreeing counterparts. Despite people’s erroneous beliefs, spoken conversation offers a promising path to disagreeing constructively.</p>