Three experiments illustrate that humor in advertisements prevents the development of negative brand associations due to resistance. Previous research on humor in advertising suggested that humor can counter negative responses during ad processing, but less is known about the effect of humor on the development of negative brand associations in memory. Brand associations are important because there is often a time delay between ad exposure and brand decisions. We separately manipulated two typical aspects of humor processing, that is, distraction and positive affect, and examined their effects on the development of respectively negative and positive brand associations. All experiments were conducted with university students as participants. The results showed that resistance causes negative brand associations (Experiments 1 and 2), and humor prevents the development of these negative brand associations more than nondistracting positive stimuli and neutral stimuli (Experiment 2 and 3). The prevention of negative brand associations was caused by the distractive properties of humor. Irrespective of resistance, the positive affect engendered by humor enhanced positive brand associations. Experiment 3 showed that distraction and positive affect in humor uniquely contribute to brand preference. Together, these results illustrate that the effect of humor on resistance follows a two-step process: humor forestalls the development of negative brand associations because of its distractive properties (cognitive mechanism), and engenders positive brand associations because of its positive emotional outcomes (affective mechanism). These effects of humor on brand associations jointly promote brand preference. (Contains 1 figure.)