 A total of 500 smokers will be enrolled from two smoking cessation clinics to participate in this study. After 2 weeks of usual treatment with 21mg patch, participants who fail to quit smoking will be randomized to receive either escalating doses of active nicotine patches, or placebo patches, for 10 weeks. Those who stop smoking during the first 2 weeks of usual treatment will continue with 21mg patch treatment for 10 weeks as an additional comparison group. In addition to the medication, participants in all groups will receive brief behavioral counselling. Subjects will return to the clinic at weeks 26 and 52 to assess whether or not they are still abstinent from smoking and self-reports of non-smoking will be confirmed using breath carbon monoxide measures and a urine test for nicotine by-product cotinine levels. 