Smoking is the leading cause of preventable diseases. The prevalence of smoking among male adults in Korea has declined rapidly. However, it is still much higher than that of the developed western countries. Evidence consistently shows that a brief smoking cessation intervention delivered by a physician increases quit rates and is highly cost-effective. As a brief strategy in the primary care setting, following the "rule of 5 A's" is recommended for patients willing to quit, and the "rule of 5 R's" for helping encourage the motivation to quit. Among the motivational interventions, which are the crucial steps for successful smoking cessation, the motivational interviewing has been tried widely and proven to be effective. Because a high proportion of quitters relapse, especially within 6 months after cessation, and continue to relapse thereafter, many studies addressing relapse prevention have been performed. However, recent metaanalytic studies have shown scant support for the interventions. Only a few studies have shown the effects of the interventions on long-term abstinence. In Korea, we have few data on the effectiveness of motivational intervention. The majority of the studies on relapse were conducted based on the smoking cessation clinics in public health centers. For effective smoking cessation counseling, we need to provide education and training for physicians, to provide economic rewards to physicians for participating in smoking cessation intervention, and to invest in research and development for smoking cessation interventions based in the primary care setting, and to develop guidelines for clinicians based on the evidences from Korean data.