OBJECTIVES: To determine the efficacy of providing online cessation intervention for college smokers. METHODS: This is a two-group randomized controlled trial. The intervention group received $10 weekly incentives to visit an online college life magazine that provided personalized smoking cessation messages and peer email support. Evaluation assessments occurred at baseline and 8, 20, and 30 weeks after enrollment. The primary outcome is self-reported 30-day abstinence at week 30. Carbon monoxide (CO) breath testing was performed for participants reporting 30-day abstinence at week 30. RESULTS: Five-hundred and seventeen college smokers at the University of Minnesota were enrolled via internet health screening (control=260, intervention=257) in the fall of 2004. Intervention participants completed an average of 18.9 (SD 2.5) of 20 weekly website visits over the course of the study. The rate of 30-day abstinence at week 30 was higher for the intervention compared to the control group (41% vs. 23%, p<0.001). CO testing showed low rates of under-reporting. There was no difference in self-reported 6-month prolonged abstinence measured at week 30. CONCLUSION: Providing personalized smoking cessation messages as part of a general interest online college life magazine increased 30-day abstinence by the end of this two semester intervention.