Distraction and relaxation have been controlled in previous studies as possible mechanisms for the effectiveness of mirthful laughter in coping with pain and discomfort. The purpose of this study is to control expectation of benefit from laughter. Discomfort thresholds for a blood pressure cuff at the upper dominant arm were recorded immediately before and after exposure to either a humorous or a relaxation video. Instructional sets led participants to believe that the video would either increase or decrease their sensitivity to discomfort. A 5th group watched the humorous video without manipulation of expectation. All participants completed A. Ziv's (1979) Sense of Humor Questionnaire (SHQZ). Humor and relaxation videos raised discomfort thresholds, and the effect of both video types was enhanced by expectations. Humorous personality trait (SHQZ) did not moderate effects. The larger issue of whether mirthful laughter has any unique benefit for pain or discomfort control beyond the effects of relaxation, distraction, or expectation is discussed.