Cross sectional studies show that most smokers in countries such as the United Kingdom and the United States report that they want to stop and intend to stop at some point.1 The rate of attempts to stop is high—78 attempts per 100 smokers per year in the UK—with many smokers making several attempts in a year.2 Nearly half of all smokers expect not to be smoking in a year's time,3 but only 2-3% actually stop permanently each year.3 The most common reasons smokers give for smoking are stress relief and enjoyment,4 but the main reason is nicotine dependence. Nicotine acts in the midbrain, creating impulses to smoke in the face of stimuli associated with smoking.5 Consequent changes in brain chemistry also produce “nicotine hunger” when a smoker goes without nicotine. A third mechanism underlying nicotine dependence is nicotine withdrawal: unpleasant mood and physical symptoms that occur on abstinence and are relieved by smoking.6 7 Nicotine dependence is the main reason that most unassisted quit attempts fail within a week.8 We give evidence based recommendations and new treatment options for healthcare professionals to increase the success rate of these attempts. Most evidence for treatment comes from randomised controlled trials summarised in the Cochrane reviews for tobacco dependence. #### Summary points