Introduction: An observational study examining 1-year follow-up of clients of two National Health Service smoking cessation services in Glasgow was used to inform a cost-effectiveness analysis. One service involved 7 weeks of group-based support (n = 411) and the other consisted of up to 12 weeks of one-to-one counseling with pharmacists (n = 1,374). Pharmacological aids to quitting (e.g., nicotine replacement therapy) were available to all clients. Methods: Quit rates were calculated for each service at 52 weeks after the quit date, and these were used for an economic evaluation of both the annual and the lifetime cost-effectiveness of the pharmacy- and group-based interventions in comparison with a baseline "self-quit" scenario. The annual cost-effectiveness model established the incremental cost per 52-week quitter, while a Markov model was developed for the lifetime analysis to estimate the potential lifetime outcomes in terms of cost per quality-adjusted life years (QALY) gained, to account for the benefits quitters will receive in terms of extended life years and improvements in quality of life from smoking cessation. Results: The proportion of carbon monoxide-validated quitters from both services combined fell from 22.5% at 4-week follow-up to 3.6% at 52 weeks. The group service achieved a higher quit rate (6.3%) than the pharmacy service (2.8%) but was more intensive and required greater overhead costs. The lifetime analysis resulted in an incremental cost per QALY of £4,800 for the group support and £2,600 for pharmacy one-to-one counseling. Conclusions: Despite disappointing 1-year quit rates, both services were considered to be highly cost-effective.