A Cochrane review included 49 trials with over 19 000 participants. 33 trials compared individual counselling to a minimal behavioural intervention. Individual counselling was more effective than control when pharmacotherapy was not offered to any participants (RR 1.57, 95% confidence interval (CI) 1.40 to 1.77; 27 studies, 11,100 participants; I2 = 50%). There was moderate-quality evidence of a benefit of counselling when all participants received pharmacotherapy (nicotine replacement therapy) (RR 1.24, 95% CI 1.01 to 1.51; 6 studies, 2662 participants; I2 = 0%). There was moderate-quality evidence (downgraded due to imprecision) for a small benefit of more intensive counselling compared to brief counselling (RR 1.29, 95% CI 1.09 to 1.53; 11 studies, 2920 participants; I2 = 48%). None of the five other trials that compared different counselling models of similar intensity detected significant differences.