The overall objective of this study was to understand the behavior of consumers who make false complaints. After a buying process, the consumer may be dissatisfied and a possible consequence is the complaint. If this claim is for a true reason, the consumer is in his right to complaints. However, the complaints may have another reason and the consumer can be an opportunist in search of some benefit. Understand what this consumer is searching is the central question of this research. Two exploratory research were conducted, one with consumers and the other with employees of Procon and Reclame.Aqui. The main reasons identified that lead a consumer to make a false complaint were: a scenario could favor the claim , the size of the company or the prestigious image in the market , the Brazilian culture to be malandro ; the first contact with the company being bad ; having financial loss to the consumer; disregard of companies with consumers , the false complaint already being considered a normal activity ; the lie be considered valid, since checking if the complaints is true is the company s responsibility, and poor communication and a bad company promotion generates adequate contexts for this type of complaint.