Participants will be randomly assigned to one of two treatments: 1) transdermal selegiline patch (STS) or 2) placebo. Treatment with STS or placebo will be given for a period of 8 weeks. Participants will be stratified by gender to evaluate the role that gender plays in moderating smoking cessation treatment. Study visits will take place once each week for 30 to 45 minutes, and will include adverse events monitoring, biochemical verification of smoking status, and a physical exam. Follow-up visits will occur at Weeks 24 and 52 to determine response to treatment.