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. 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. 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. Despite disappointing 1-year quit rates, both services were considered to be highly cost-effective.