The goal of this longitudinal study was to test an innovative approach to smoking cessation that might be particularly attractive to adolescent smokers. The study was a participatory research effort between academic and school partners. The intervention used an Internet-based, virtual reality world combined with motivational interviewing conducted in real-time by a smoking cessation counselor. Participants were 136 adolescent smokers recruited from high schools randomized to the intervention or a measurement-only control condition. Those who participated in the program were significantly more likely than controls to report at the immediate post-intervention assessment that they had abstained from smoking during the past week (p<or=.01), smoked fewer days in the past week (p<or=.001), smoked fewer cigarettes in the past week (p<or=.01), and considered themselves a former smoke (p<or=.05). Only the number of times quit was statistically significant at a one-year follow-up assessment (p<or=.05). The lack of longer-term results is discussed, as are methodological challenges in conducting a cluster-randomized smoking cessation study.