AbstractAimsTo measure how cigarette packaging (standardised packaging and branded packaging) and health warning size affect visual attention and pack preferences among Colombian smokers and non‐smokers.DesignTo explore visual attention, we used an eye‐tracking experiment where non‐smokers, weekly smokers and daily smokers were shown cigarette packs varying in warning size (30%‐pictorial on top of the text, 30%‐pictorial and text side‐by‐side, 50%, 70%) and packaging (standardised packaging, branded packaging). We used a discrete choice experiment (DCE) to examine the impact of warning size, packaging and brand name on preferences to try, taste perceptions and perceptions of harm.SettingEye‐tracking laboratory, Universidad Nacional de Colombia, Bogotá, Colombia.ParticipantsParticipants (n = 175) were 18 to 40 years old.MeasurementsFor the eye‐tracking experiment, our primary outcome measure was the number of fixations toward the health warning compared with the branding. For the DCE, outcome measures were preferences to try, taste perceptions and harm perceptions.FindingsWe observed greater visual attention to warning labels on standardised versus branded packages (F[3,167] = 22.87, P < 0.001) and when warnings were larger (F[9,161] = 147.17, P < 0.001); as warning size increased, the difference in visual attention to warnings between standardised and branded packaging decreased (F[9,161] = 4.44, P < 0.001). Non‐smokers visually attended toward the warnings more than smokers, but as warning size increased these differences decreased (F[6,334] = 2.92, P = 0.009). For the DCE, conditional trials showed that increasing the warning size from 30% to 70% reduced preferences to try (odds ratio [OR] = 0.48, 95% CI = [0.42,0.54], P < 0.001), taste perceptions (OR = 0.61, 95% CI = [0.54,0.68], P < 0.001); and increased harm perceptions (OR = 0.78, 95% CI = [0.76,0.80], P < 0.001). Compared with branded packaging, standardised packaging reduced our DCE outcome measures with ORs ranging from OR = 0.25 (95% CI = [0.17,0.38], P < 0.001) to OR = 0.79 (95% CI = [0.67,0.93], P < 0.001) across two brands. These effects were more pronounced among non‐smokers, males and younger participants. Unconditional trials showed similar results.ConclusionsStandardised cigarette packaging and larger health warnings appear to decrease positive pack perceptions and have the potential to reduce the demand for cigarette products in Colombia.