There are over 300 million Chinese smokers, but use of nicotine replacement therapy (NRT) is rare. On the other hand, data on the factors associated with quitting and adherence to NRT use are scarce in the East. To describe adherence and other predictors of quitting smoking at the 12-month follow-up amongst Chinese smokers in Hong Kong. Chinese smokers (1186) who attended the Smoking Cessation Health Centre from August 2000 through January 2002 were studied. Trained counsellors provided individual counselling and carried out follow-up interviews. We used structured questionnaires at baseline and at 1, 3 and 12 months and an intention-to-treat approach for analysis. Among those who received NRT (1051/1186), the prevalence of adherence (self-reported NRT use for at least 4 weeks) was 16% (95% confidence interval 14-18%). The 7-day point prevalence quit rate at 12 months (not smoking any cigarette during the past 7 days at the 12 month follow-up) was 27% (95% CI, CI 24-29%). Stepwise logistic regression model showed that adherence to NRT use, a higher income, good perceived health and having more confidence in quitting were significant predictors of quitting. The quit rate in the adherent group (40%) was greater than that of the non-adherent group (25%) (P<0.001). Older age, male, higher education, experience of NRT use, perceiving quitting as more difficult and willingness to pay were significant predictors of adherence. Clinically significant smoking cessation rates can be achieved among Chinese smokers in a clinic-based smoking cessation service. The NRT adherence was low and low adherence was associated with a lower quit rate. Trials of interventions to improve adherence and increase quit rates are needed.