Four hundred and thirty-five Chinese smokers who had attended the first smoking cessation clinic and received stage-matched individualized cessation counseling in Hong Kong during the period of August 2000 to January 2002 were successfully followed-up between February and August 2008. Some 38% of the participants (165/495) had stopped smoking during the 12-month follow-up after treatment. Participants with higher conscientiousness score (OR = 1.65, 95% CI: 1.09 - 2.48) and lower openness to experience score (OR = 0.64, 95% CI: 0.45 - 0.92) showed a greater likelihood of quitting smoking after controlling the effect of daily cigarettes smoked and stage of readiness at baseline. The study suggests an important role of conscientiousness and openness to experience on long-term quitting behaviors following treatment, and provides useful information for the development of matched intervention for smoking cessation among Chinese smokers.