The Collaborative European Anti-Smoking Evaluation (CEASE) was a European multicentre, randomized, double-blind placebo controlled smoking cessation study. The objectives were to determine whether higher dosage and longer duration of nicotine patch therapy would increase the success rate. Thirty-six chest clinics enrolled a total of 3,575 smokers. Subjects were allocated to one of five treatment arms: placebo and either standard or higher dose nicotine patches (15 mg and 25 mg daily) each given for 8 or 22 weeks with adjunctive moderately intensive support. The 12 month sustained success rates were: 25 mg patch for 22 weeks (L-25), 15.4%; 25 mg patch for 8 weeks (S-25), 15.9%; 15 mg patch for 22 weeks (L-15), 13.7%; 15 mg patch for 8 weeks (S-15), 11.7%; and placebo (P-0) 9.9% (placebo versus 15 mg, p<0.05; 25 mg versus 15 mg, p<0.03; 25 mg versus placebo, p<0.001, Chi-squared test). There was no significant difference in success rate between the two active treatment durations. Of the first week abstainers (n=1,698), 25.1% achieved success at 12 months as opposed to first week smokers, 2.7% of 1,877 subjects (p< 0.001). In summary, a higher than standard dose of nicotine patch was associated with an increase in the long-term success in smoking cessation but continuation of treatment beyond 8-12 weeks did not increase the success rates.