The primary care setting is an important place for promoting smoking cessation. Randomized clinical trials (RCTs) testing the effect of brief smoking interventions and comprehensive programs delivered in a primary care setting present excellent evidence that such interventions significantly increase patients' smoking cessation rates and that as the dose of intervention increases, the effect increases. Unfortunately, despite widespread dissemination of preventive services guidelines and positive physician attitudes towards such services, the current level of delivery of smoking cessation intervention by physicians in real-world settings is not high, making this a major research and public health concern. Interventions to increase the rate of implementation provider-delivered brief smoking interventions can be grouped broadly into: provider education; clinical systems and procedures (e.g., screening and tracking of patients); and organizational policy (e.g., reimbursement, coverage, performance measures). Given the significant effect that primary care-based interventions can have on smoking cessation, it is important to investigate methods to increase their rate of delivery and their effect. Examples of research to motivate to intervene questions include: what are the best incentives or combination of incentives for physicians? What are the most effective strategies to remind providers to intervene? How can each of these be best implemented in different types of settings and systems? How can a stepped-care and patient-treatment matching model be used? The study of factors such as reimbursement policies and covered benefits do not lend themselves well to tightly-controlled randomized trials. Therefore, use of quasi-experimental designs, and application of qualitative strategies are needed. These designs represent a different challenge to the research community.