The authors investigated relationships among sense of humor measured by a questionnaire, attentional bias toward humor measured by performance on a word-search task, and experimentally induced mood change through the use of sad and humorous cartoons. Mood was significantly altered in a negative direction after the sad cartoon. Coping humor, part of the sense of humor questionnaire, was associated with less negative mood ratings after the sad cartoon. In terms of main effects, only a modest change in mood was found after the humorous cartoon. Humor bias was associated with more positive mood ratings after the humorous cartoon. The authors suggest that coping humor serves a protective psychological function, helping screen the person from negative stimuli and, thus, from negative reactions. Attentional bias toward humor serves a different protective psychological function by helping the person focus on mood-enhancing stimuli in the environment.