The purpose of this study was to analyze the post-purchase behavior of customers who experienced cognitive dissonanceafter exposure to a franchise foodservice advertisement. The study adopted cognitive dissonance theory to explain thedissonance resulting from the combination of advertisements and actual product that consumers received. In detail, theresearch hypothesized that cognitive dissonance will affect consumers’ post-purchase behavior as well as their efforts toreduce dissonance. Exactly 274 questionnaires were used in the analysis. The results showed that more than 80% ofrespondents were influenced by advertisements when purchasing menus, and 50% were unsatisfied when the providedmenu “was not the same as the advertisement shown.” It was found that advertisement type did not significantly affect eithergroup that experienced dissonance. In terms of satisfaction, however, the former group showed greater dissatisfaction whendissonance occurred (p<.001). Finally, there was a significant difference between the two groups regarding post-purchasebehavior (p<.05). Customers with dissonance were likely to ‘express dissatisfaction directly to the store’, ‘leave negativereviews’, and ‘participate in negative word-of-mouth’. Thus, the results revealed that cognitive dissonance could significantlyinfluence customer satisfaction and consequently lead to negative post-purchasing behaviors.