Abstract This study compares the impact of pictorial health warning labels (HWLs) and their placements on waterpipe parts (device, tobacco and charcoal packages) on health communication outcomes between waterpipe smokers and nonsmokers in Lebanon. An online randomized crossover experimental study was conducted among young adults (n = 403, August 2021) who observed three conditions of HWLs: pictorial HWLs on the tobacco package, pictorial HWLs on all waterpipe’s parts and text-only HWL on the tobacco package in random order. Participants completed post-exposure assessments of health communication outcomes after each image. Using linear mixed models, we examined the differences in the effect of HWL conditions on several outcomes (i.e. warning reactions) between waterpipe smokers and nonsmokers, controlling for confounders (i.e. age, sex). Nonsmokers reported greater attention (β = 0.54 [95% confidence interval: 0.25–0.82]), cognitive elaboration (0.31 [0.05–0.58]) and social interaction (0.41 [0.18–0.65]) for pictorial HWLs on the tobacco packages than text-only compared with smokers. Pictorial HWLs on three parts versus one part elicited higher cognitive reactions and perceived message effectiveness in nonsmokers compared with waterpipe smokers. These findings provide valuable information for policymakers about the potential of implementing HWLs specific to waterpipes to prevent their use among young adults and limit tobacco-related morbidity and mortality in Lebanon.