Background Telephone-based smoking cessation services (quitlines) offering counselling for smoking cessation without nicotine replacement therapy may be important components of tobacco control efforts in low and middle income countries, but evaluations in such resource-limited settings are lacking. We aimed to evaluate the usage, effectiveness and cost of the Thailand National Quitline (TNQ).

Methods Analysis of retrospective data for callers to the TNQ between 2009 and 2012 and a follow-up survey in 1161 randomly selected callers.

Results Between 2009 and 2012 there were 116 862 callers to the TNQ; 36 927 received counselling and at least one follow-up call. Compared with smokers in the general population, callers were younger, more highly educated, more likely to be students, and more likely to smoke cigarettes rather than roll-your-own tobacco. Continuous abstinence rates at 1, 3 and 6 months after calling were 49.9%, 38.0% and 33.1%. The predicted rate at 12 months was 19.54% (95% CI 14.55 to 26.24). Average cost per completed counselling was $31 and the average cost per quitter was $253. Assuming all (and two-thirds) TNQ callers who succeed in quitting would have failed to quit without the assistance of the TNQ, cumulative life years saved (LYS) for the 4-year period were 57 238 (36 733) giving a cost per LYS of $32 (50) (about 7.93 LYS per quitter) and an estimated return on investment over 4 years of 9.01 (5.78).

Conclusions A low-cost quitline without nicotine replacement therapy is a promising model for smoking cessation services and likely to offer good value for money in Thailand.