Abstract This study evaluated the relative efficacy and cost-effectiveness of a stop smoking clinic and self-help kit, and characteristics of those who benefited most from each approach. Employees attended an orientation of quit smoking programs that included a brief description of the American Lung Association's "Freedom From Smoking" clinic and "Freedom From Smoking in 20 Days" self-help kit. Seventy registrants provided both baseline and 18-month follow-up information by questionnaire. The two methods attracted smokers with somewhat different socio-demographic characteristics. The combined quit rate for the two groups was 17 percent at 18 months. Cost per participant was twice as high for the clinic method ($32 vs. $16), but cost per successful quitter was similar in both groups (about $150). In light of these results, employees should continue to be offered a choice of self-help and clinic approaches to smoking cessation in order to reach the largest potential number of participants.