Objective. Evaluate how conversations about health warning labels (HWLs) influence attempts to quit smoking (QAs) and sustained attempts to quit (SQAs) among in Mexican adult who smoke. Materials and methods. Data were analyzed from a cohort of 2 164 participants surveyed every four months between November 2018 and March 2021. Multinomial models regressed the frequency of talking about HWLs on sociodemographics and smoking-related variables. Generalized Estimating Equations assessed whether the effect of HWL talking frequency on QAs and, separately, SQAs at follow-up was mediated by the topic of conversation. Results. The majority reported having talked about HWLs (63.7%), regarding the harms of tobacco (73.3%), cessation benefits (58.5%), and lack of credibility/utility of HWLs (9.8%). At follow-up, 42.0% reported an QAs and 20.7% an SQAs. Conversations about HWLs were more frequent among younger participants, those with a university education, those who had recently attempted to quit smoking, and those intending to quit. Talking about HWLs was associated with a higher frequency of QAs and SQAs, mediated equally by discussions about cessation benefits and tobacco harms. Conclusion. Conversation topics around HWL are mesassociated with more smoking cessation attempts. Mexican HWLs focus primarily on harms, more research is needed to evaluate the optimal mix of content.