Exposure to alcohol ads increases alcohol consumption. A potential partial explanation is that certain (e.g., humorous) alcohol ads trigger conversations which can, in turn, increase drinking behaviors. Therefore, we investigated the influence of humor in alcohol ads on conversational occurrence, length, and valence about alcohol and alcohol ads. One hundred and fourteen participants were shown one of three beer ads (humor; positive; no ad), after which participants could voluntarily discuss the ad and alcohol. Next, all participants were requested to discuss the topic and answered a questionnaire assessing conversational valence and ad, brand, and alcohol evaluations. Results showed that humor leads to more conversations about the ad and alcohol, longer conversations about alcohol, and more positive conversations about the ad. This interpersonal communication, and especially conversational valence, was subsequently related to ad, brand, and alcohol evaluations. These findings may explain the effect of alcohol ads on alcohol consumption, and provide important starting points for using humor as a potentially effective behavior change tool.