Objective: The use of visuals in tobacco product advertising is a prevalent and effective way to communicate implicit messages to consumers. Tobacco companies heavily rely on visual messaging due to regulatory limitations on explicit statements and claims in their advertising. Research on how visuals influence our perception of advertised products is limited. This dissertation argues that research on the effects of tobacco product advertising should devote more focus on the study of visual persuasion especially in the context of products that pose harm to public health. Methods: This dissertation reports on findings from two studies that use quantitative and qualitative methods: (1) A 3 (warning type) x 3 (message type) + 3 control online experiment with young adult and (2) 16 online focus groups with youth and adults. Through both methodological approaches, I examine the influence of visuals in e-cigarette advertisements on participants’ emotional and cognitive responses, as well as their perceptions of e-cigarettes and advertisements. Findings: Participants pay attention to a variety of different visual cues, particularly color, warning labels, models, e-cigarette products and devices, and visual presentational features. Moreover, participants use visual cues to form their perception of the advertisement they are viewing and the advertised product. Most important is that some visual cues elicited positive emotion for some participants, which consequently improved their perceptions of the ad. Conclusion: We recommend that future research examines the mechanisms through which different visual cues influence product perceptions and consequently adoption of the product (e-cigarettes in the case of this work). Conclusion and implications: Visuals can influence emotional responses and attitudes towards advertised products, as well as improve consumers’ ad perceptions. I recommend that future research examines the potential persuasiveness of different visual cues and the mechanisms through which visuals influence viewers. Regulatory bodies also should consider how to regulate implicit visual messages in advertising, because current guidelines are unclear about how implied claims are assessed and regulated.