CONTEXT: Effective clinic-based, smoking-cessation activities are not widely implemented. OBJECTIVE: To compare and contrast the smoking-cessation attitudes and clinical practices of five types of primary healthcare team members. DESIGN AND SETTING: From July to October 2002, a cross-sectional survey was mailed to randomly selected primary care physicians (MDs), advanced practice nurses (APRNs), registered nurses (RNs), licensed practical nurses (LPNs), and medical assistants (MAs). MAIN OUTCOME MEASURES: Factors associated with limited smoking-cessation service delivery. RESULTS: The overall response rate was 68% (n =3021). Most respondents reported that patients' smoking status was consistently documented at their clinic (79%); other system prompts were less common (30%). Many respondents reported documenting smoking status or recommending quitting; few reported consistently assessing, assisting, or arranging follow-up. The mean rank of smoking cessation as an important preventive service among nine preventive services declined from MDs (1.9) to APRNs (2.5), RNs (3.4), LPNs (4.2), and MAs (4.6). Smoking prevalence increased from 1% in MDs to 3% APRNs, 9% RNs, 17% LPNs, and 22% MAs. Those who reported no consistent smoking-cessation service delivery were more likely to be RNs, LPNs, or MAs, currently smoke, and work more hours. They were less likely to consider patients receptive to cessation messages, to consider themselves qualified to counsel on smoking, or to work in clinics that had smoking-cessation guidelines or system prompts such as chart reminders. CONCLUSIONS: Smoking-cessation service delivery may be enhanced if educational offerings, system changes, and training include all clinical staff members.