This study demonstrates the facilitating effect of positive mood on brand attitudes for readers of print advertising and explores contingencies and cognitive processes underlying that effect. Mood appears to affect the amount of total cognitive elaboration, bias the evaluation of argument quality, and peripherally affect brand attitudes. An experiment using print ads reveals that positive moods create less elaboration, which results in more heuristic processing and reduces the extent to which message evaluation—itself favorably influenced by positive moods—mediates brand attitudes. The effect is greater when the reader has a low need for cognition and when the ad contains weak message arguments.