Background: Pharmacological strategies to improve smoking cessation have been largely studied. The efficacy of cognitive behavior therapy associated to nicotine replacement in tobacco cessation has not yet been demonstrated.

Objective: Evaluate if cognitive behavior therapy during six weeks associated to nicotine replacement for twelve weeks is able to contribute to tobacco cessation at the end of 52 weeks.

Methods: Multicentre, open-label, and pragmatic randomized controlled trial will include 334 patients. Analysis will follow intention-to-treat principle.

Patients older than 18 years old and who had smoked at least 5 cigarettes in the past year before randomization will be included.

All of them will receive nicotine replacement therapy with patches and gum. They will be randomized 1:1 ratio to attend or not cognitive behavior therapy once a week for the first six weeks of the treatment. Every two weeks all of the patients will be evaluated by a physician in order to access any adverse effects from the nicotine replacement.

All patients will have carbon monoxide levels accessed at baseline and after 6 weeks. Telephonic interview will be done at 16, 28, and 52 weeks to access the rates of tobacco cessation, relapses episodes and abstinence maintenance.

Inclusion Criteria:

• Smokers (≥ 5 cigarettes/day during the previous year) who had not had a period of abstinence greater than 3 months before randomization
• Age ≥ 18 years < 75 years;
• Capable of reading and understanding Portuguese;
• Willing to quit smoking.

Exclusion Criteria:

• Dementia;
• Alcoholism;
• Regular use of illicit drugs;
• Panic disorders;
• Psychosis;
• Current pregnancy;
• History of bipolar disturbance;
• Contraindication to nicotine patches;
• Prior use of bupropion and/or varenicline in the previous 12 months before randomization;
• Patients who refused to provide informed consent;