More than 100 countries have implemented pictorial health warnings on cigarette packages. However, few studies have compared how consumers from different geographic and cultural contexts respond to health warning content. The current study compares perceptions of warnings among adult smokers and youth in seven countries, to examine the efficacy of different health warning themes and images. Between 2010 and 2012, online and face-to-face surveys were conducted with ~500 adult smokers and ~500 youth (age 16-18) smokers and nonsmokers in each of Mexico, United States, China, Germany, India, Bangladesh, and Republic of Korea (total N = 8182). Respondents were randomized to view and rate sets of 5-7 health warnings (each set for a different health effect); each set included a text-only warning and various types (ie, themes) of pictorial warnings, including graphic health effects, "lived experience," symbolic images, and personal testimonials. Mixed-effects models were utilized to examine perceived effectiveness of warning themes, and between-country differences in responses. Overall, pictorial warnings were rated as more effective than text-only warnings (p < .001). Among pictorial themes, "graphic" health effects were rated as more effective than warnings depicting "lived experience" (p < .001) or "symbolic" images (p < .001). Pictorial warnings with personal testimonials were rated as more effective than the same images with didactic text (p < .001). While the magnitude of differences between warning themes varied across countries, the pattern of findings was generally consistent. The findings support the efficacy of graphic pictorial warnings across diverse geographic and cultural contexts, and support sharing health warning images across jurisdictions. Although over 100 countries have implemented pictorial health warnings on cigarette packages, there is little research on the most effective types of message content across geographic and cultural contexts. The current study examined perceived effectiveness of text and pictorial health warnings featuring different message content-graphic health effects, "lived experience," personal testimonials, and symbolic imagery-among more than 8000 adults and youth in Mexico, United States, China, Germany, India, Bangladesh, and Korea. Across countries, "graphic" pictorial messages were rated as most effective. Consistencies across countries in rating message content suggests there may be "globally effective" themes and styles for designing effective health warnings.