OBJECTIVE To evaluate the effectiveness of a large group community-based behavioral smoking cessation intervention over an 8-year follow-up period and to determine precessation predictors of cessation at each follow-up time. METHODS Behavioral intervention followed by three longitudinal follow-up interviews. METHODS Regional Outpatient Cancer Centre. METHODS 971 participants in smoking cessation clinics held between 1986 and 1990. METHODS Eight 90-minute sessions over 4 months utilizing education, self-monitoring, nicotine fading, a group quit date and behavioral modification techniques. Up to 110 smokers participated in each group program. METHODS Cessation rates at 3, 6, and 12 months postquit and at 8-year follow-up. Differences between successful and unsuccessful participants in precessation demographic, smoking history, and smoking behavior variables. RESULTS At 3 months postquit date, 39.3% of the 971 participants reported that they were not smoking, decreasing to 32.1% at 6 months and 26.0% at 12 months. At the 8-year follow-up, 33.9% of the original sample were contacted, and of those, 47.7% reported that they were currently not smoking. There were nine predictors of cessation at the end of the program (3 months), which were similar to those previously reported in the literature. Similarly, at 6 and 12 months, six factors were associated with not smoking. At the 9-year follow-up the only variable predictive of continued abstinence was being female (p < .05). CONCLUSIONS This program was successful in promoting smoking cessation and maintenance, even with its large-group format. Predictive factors were similar to those previously reported in the literature.