Humor is a potential communication strategy to accomplish various and potentially conflicting consultation goals. We investigated humor use and its reception in diabetes consultations by analyzing how and why humor emerges and its impact on the interaction. We did this by using an interactional sociolinguistics approach. We recorded 50 consultations in an Irish diabetes setting. Analysis of the humor events drew on framework analysis and on concepts from Conversation Analysis and pragmatics. The study also comprised interviews using tape-assisted recall. We identified 10 humor functions and two umbrella functions. A key finding is that most humor is relationship-protecting humor initiated by patients, that is, they voice serious messages and deal with emotional issues through humor. Our findings imply that patients’ and providers’ awareness of indirect communication strategies needs to be increased. We also recommend that researchers employ varied methods to adequately capture the interactive nature of humor.