Objective: To calculate incremental cost-utility ratios for an additional 12-weeks varenicline treatment as compared to the initial 12 weeks (successful) varenicline treatment for a 50-year follow-up period. Methods: The Benefits of Smoking Cessation on Outcomes (BENESCO) model was used to simulate costs and benefits accruing from smoking cessation for a Swedish male (168,844 males) and female cohort (208,737 females), respectively. The smokers made one quit attempt at the outset of the simulated period. The model was extended in order to include indirect effects of smoking cessation on production and consumption due to increased survival. Smoking cessation benefits were modelled through lower incidence rates of chronic obstructive pulmonary disorder, coronary heart disease, stroke, and lung cancer in those who quit. All calculations were performed in 2003 Swedish prices, and transformed into Euros. Results: Varenicline used for 12 weeks in smoking cessation therapy in comparison to bupropion has been shown to be a very cost-effective treatment. A recent study showed that 12 weeks of additional varenicline treatment in successful quitters will help to maintain smoking bstinence. Including only healthcare costs, the estimated incremental cost per QALY gained was €7066 and €7108, respectively, for men and women. Taking also indirect effects on production and consumption of increased survival into account, the corresponding figure was about €24,000 for both men and women. Performed simulations over a 50 year follow-up period imply that about 19,176 life years are saved. This corresponds to €8945 QALYs. Sensitivity analyses indicated that the results are robust. Conclusion: An additional 12-weeks course of varenicline provided to successful quitters produces low incremental cost-utility ratios in the spectrum of life-saving medical treatments.