This thesis examines the usage of puffery in advertising. Puffery refers to highly exaggerated or “over-the-top” claims and is commonly used as a legal defense when advertising is alleged to be misleading or deceptive, given that a “reasonable” consumer should not believe a “puffed” claim. Using a mixed method approach and Vitaminwater as the focal product, this thesis investigates whether “puffed” claims, despite being highly exaggerated and largely non-believable, are likely to be persuasive to consumers and consequently misleading. First, a semiotic analysis of Vitaminwater advertising and labeling was carried out to illustrate the use of puffery in the brand’s marketing communication and the potential for such claims being misleading. Second, an experimental study was conducted that exposed participants to Vitaminwater advertisements possessing verbal or visual puffery claims, non-puffery claims, or a control condition. Participants were asked to fill out a self-response questionnaire pertaining to the advertisements they were shown, including measures relating to their involvement, general attitudes toward the ad, believability toward the claims or claim credibility, purchase intentions, as well as the perceived healthiness of the product. The research sheds light on the legal aspects of deception in advertising and informs policy makers and regulators about the potential influence of puffery. Results show that policy makers should potentially re-evaluate statements regarding deceptive/misleading advertisements that contain puffery as they can be persuasive regardless if a claim is direct or implied in the advertisements.