Smoking is a well established cause of chronic lung disease and is the leading preventable behavior contributing to patient morbidity and mortality. Smoking cessation has been shown to have a strong beneficial effect on the course of chronic obstructive pulmonary disease (COPD). Research has clearly established that physician advice regarding smoking cessation will significantly increase the likelihood that a patient will quit smoking. There are five steps recommended as a starting point for the clinician addressing smoking cessation. The 5 A's include ‘asking’ the patient about smoking, ‘advising’ cessation, ‘assessing’ readiness to quit, ‘assisting’ in the process, and ‘arranging’ follow-up. If the patient is unwilling to quit smoking, the 5 R's can be employed: emphasizing ‘relevance’ of cessation, identifying ‘risks’ of smoking, focusing on ‘rewards’, discussing ‘roadblocks’, and using ‘repetition’. Pharmacologic therapy is recommended for most patients seriously considering smoking cessation with few exceptions. Nicotine replacement therapy and bupropion are considered first-line agents. Combination therapy may be used in patients who are not successful in quitting while using single-drug therapy. Despite evidence that clinician advice to quit smoking increases abstinence rates, clinicians inconsistently intervene. System-based programs provide opportunities to further improve rates of smoking cessation.