Nicotine replacement therapy (NRT) has added to the menu of options available to assist cigarette smokers in quit attempts, but cost remains a barrier to access. A quasi-experimental study was carried out to compare quit rates and continuous abstinence from smoking before (n=601) and after (n=311) free nicotine patches were offered to smokers who participated in the Washington County (Maryland) Health Department's "Stop Smoking for Life" group behavioral cessation program. After free NRT was offered, the quit rates upon completion of the program increased from 38% to 65% [difference 27%; 95% confidence limits (CL) 21%, 34%]. The difference in continuos abstinence from smoking between the two groups was no longer statistically significant after 6 months of follow-up, reflecting the more rapid rate of reversion to smoking that occurred during the 18-month follow-up period among the free NRT group who had quit [adjusted rate ratio (RR) 1.35; 95% CL 1.03, 1.78]. Enrollment during the first 18 months after free NRT was 37% greater than the program's first 18 months (P=.08). In conclusion, adding free nicotine patches to a smoking cessation program was associated with increased program enrollment and significantly increased short-term-but not long-term-quit rates. The rapid reversion to smoking in the group who received free nicotine patches could potentially be obviated if participants extend their use of nicotine patches after the free 6-week supply is exhausted.