This dissertation begins with the study of the actual customer's behaviours toward advertising. The purpose of the research is to seek how the customers react toward ads using the threat appeal. In a first phase of her work the researcher explores the existing theories through a critical literature review. She defines the key theories and concepts, and exposes the findings of some existing surveys about the efficiency of the fear appeal in road safety advertising campaigns. After this familiarisation with the subject, the researcher checks if it is possible to apply these findings on the FMCG market. The objective of this study is to evaluate how the use of fear in advertising can be effective. The research question set up by the researcher is ‘Does the use of threat appeal pay?’ This thesis is also about the ethical aspect of this use. We will investigate about the limits of this negative stimulus as a factor of motivation. In order to proceed, the researcher has first conducted on a qualitative survey by the method of focus groups. This primary research was used to build up the quantitative research, a self-administrated questionnaire. The findings showed that the use of threat appeal pay in the manner that it is a good way to catch the customer's attention. However, this appeal must be carefully used by advertisers: the prior statement doesn't mean that the ad touches the customers in a positive way. The image resulted from an advertisement using the threat appeal can be negative and have some bad consequences on the product or brand image. This dissertation contributes to enrich the existing knowledge about the topic as the researcher identified that the acceptance of the threat appeal does not only depend about the level of threat used; it is strongly related to the nature of the product advertised. The customers are more likely to appreciate the fear arousal if the message given has also some social objectives.