Participant attendance at smoking cessation-counseling sessions is an important factor in treatment outcome. In this study, we examined the influence of demographic, psychological, and smoking history variables on attendance at a randomized clinical trial comparing transdermal nicotine and nicotine nasal spray that included seven sessions of behavioral group counseling. Of the 353 participants, 70.5% attended all seven sessions. Perfect attendance predicted abstinence from cigarettes at the end of treatment and at 6-month follow-up. In a logistic regression model, higher levels of education and higher body mass index were significant independent predictors of better attendance. There was a significant interaction between type of nicotine replacement (transdermal nicotine vs. nasal spray) and sex: females were less likely than males to have perfect attendance in the nasal spray group, but there was no sex difference in attendance for the transdermal nicotine group. These findings suggest that smokers with lower body mass index and less formal education may benefit from proactive counseling to address individual barriers to attendance at smoking cessation counseling. Additional research in this area would also be valuable to evaluate strategies to promote attendance in these high-risk groups.