BACKGROUND: Smoking remains the leading cause of preventable mortality in the US. The national clinical guideline recommends an intervention for tobacco use known as the 5-As (Ask, Advise, Assess, Assist, and Arrange). Little is known about the model's effectiveness outside the research setting. OBJECTIVE: To assess the effectiveness of tobacco treatments in HMOs. PARTICIPANTS: Smokers identified from primary care visits in nine nonprofit health plans. DESIGN/METHODS: Smokers were surveyed at baseline and at 12-month follow-up to assess smoking status and tobacco treatments offered by clinicians and used by smokers. RESULTS: Analyses include the 80% of respondents who reported having had a visit in the previous year with their clinician when they were smoking (n = 2,325). Smokers were more often offered Advice (77%) than the more effective Assist treatments-classes/counseling (41%) and pharmacotherapy (33%). One third of smokers reported using pharmacotherapy, but only 16% used classes or counseling. At follow-up, 8.9% were abstinent for >30 days. Smokers who reported being offered pharmacotherapy were more likely to quit than those who did not (adjusted OR = 1.73, CI = 1.22-2.45). Compared with smokers who didn't use classes/counseling or pharmacotherapy, those who did use these services were more likely to quit (adjusted OR = 1.82, CI = 1.16-2.86 and OR = 2.23, CI = 1.56-3.20, respectively). CONCLUSIONS: Smokers were more likely to report quitting if they were offered cessation medications or if they used either medications or counseling. Results are similar to findings from clinical trials and highlight the need for clinicians and health plans to provide more than just advice to quit.