Objective: To estimate the incremental cost-effectiveness ratio of a structured community pharmacist-based smoking cessation programme compared with usual care.Design: A cost-effectiveness study using a healthcare system perspectivePopulation: Two simulated cohorts of smokers: male and female aged 40, 50 and 60 years who regularly smoke 10-20 cigarettes per day.Intervention and comparator: A structured community pharmacist-based smoking cessation (CPSC) programme compared to usual care.Main outcome measure: Cost per life year gained (LYG) attributable to the smoking cessation programme.Results: The CPSC programme results in cost savings of 17 503.53 baht ([pounds]250; [Euro sign]325; $500) to the health system and life year gains of 0.18 years for men and; costs savings of 21 499.75 baht ([pounds]307; [Euro sign]399; $614) and life year gains of 0.24 years for women. A series of sensitivity analyses demonstrate that both cost savings and life year gains are sensitive to variations in the discount rate and the long-term smoking quit rate associated with the intervention.Conclusion: From the perspective of the health system, the CPSC programme yields cost savings and life year gains. This finding provides important information for health policy decision-makers when determining the magnitude of resources to be allocated to smoking cessation service in community pharmacy.