Background: In the Fit2Quit randomised controlled trial, insufficiently-active adult cigarette smokers who contacted Quitline for support to quit smoking were randomised to usual Quitline support or to also receive= 7 contacts), the ICER for point prevalence was NZ$ 3,991 (US$ 2,695 or (sic)2,105 PPP-adjusted). In this adherent subgroup, the Markov model estimated 0.057 and 0.068 discounted quality-adjusted life-year gains over the lifetime of 40-year-old males (ICER: NZ$ 4,431; US$ 2,993 or (sic)2,337 PPP-adjusted) and females (ICER: NZ$ 2,909; US$ 1,965 or (sic)1,534 PPP-adjusted). Conclusions: The exercise-counselling intervention will only be cost-effective if adherence is a minimum of >= 7 intervention calls, which in turn leads to a sufficient number of quitters for health gains.