The use of humor has become common practice in advertising; yet our knowledge about its impact has not been updated since the last major review almost twenty years ago. In the interim, a great deal of humor research has been conducted. The outcome of this research only partially supports earlier conclusions and highlights the need to apply humor with care. Humor is by no means a guarantee of better ads, but its effect can be enhanced with careful consideration of the objectives one seeks to achieve as well as the audience, situation, and type of humor.