This study investigates gain-framed and loss-framed messages on graphic cigarette warning labels and their effects on adolescents' smoking-related attitudes and behaviors. Canadian cigarette warning labels emphasizing health consequences of smoking (loss-framed) were digitally manipulated into gain-framed versions. High school students (N = 210) completed a questionnaire measuring attitudes, perceptions of the warnings, and behavioral intentions. The study used a posttest-only comparison group design with random assignment. The independent variable was message framing (loss-framed, gain-framed avoidance, gain-framed benefits), and the dependent variables were (a) attitudes toward the warning, (b) attitudes toward smoking, (c) effectiveness in reducing smoking levels, (d) intentions to smoke, (e) effectiveness in improving one's ability to quit, and (f) effectiveness in increasing the likelihood of a smoker quitting. Results indicate that adolescents had more favorable attitudes toward the loss-framed warnings and perceived them as more effective than the gain-framed warnings. Further, smokers exposed to the loss-framed version featuring decaying teeth had significantly lower intentions to smoke in the future. Loss-framed warning labels appear to have a positive influence on adolescents' smoking-related attitudes and behavioral intentions.