Visual communication has been identified as an important area both in research and in practice in health communication. In the context of skin cancer, previous work predominantly focused on the individual contribution of visuals or texts to the effects on comprehension and behavioral intentions. However, communication about skin cancer is usually multimodal – using more than one type of semiotic messages, such as picture, music, and language, to convey information and meaning. Few studies have examined the relationship between different semiotic messages, such as the congruency between language and picture. In addition, little is known about the effects of multimodal portrayals on attitudes and behavioral intentions. To address the gap in the literature, a study was created to examine the multimodal portrayal of skin cancer in women’s popular magazines and the effects of such portrayals on attitudes and behavioral intentions of indoor tanning. The study presented in the dissertation employed mixed research methods and was composed of two studies. The first drew on a lens of multimodal discourse analysis and examined how pictures and texts interactively constructed a multimodal discourse about skin cancer in women’s popular magazines. The findings suggested that pictures and texts conveyed two competing discourses about skin cancer. Drawing on the findings of the first study, the second study was created to examine the effects of such multimodal portrayals on attitudes and behaviors. Incorporating a perspective of pictorial superiority effects, the experiment aimed to find out whether visual messages are more powerful than words in shaping people’s attitudes and behavioral intentions, especially when words and images are incongruent in terms of message orientation. Overall, findings of the second study revealed that PSE was context-specific and was only observed when picture and text were viewed in isolation. Overall, findings from the experiment did not provide sufficient evidence to support PSE since participants across text-picture combination conditions uniformly reported high levels of intentions of tanning bed uses (6-10 times) in the next three months. Theoretical and practical implications of the two studies were discussed.