The aim of this study is to evaluate a new cognitive behavioral smoking reduction program for ambulant patients in a three-armed study design. Study participants will be randomized to one of the following three study groups: experimental group: 5-week lasting cognitive behavioral reduction program ("smoke_less"); active comparator: 15 minutes counseling interview; waiting group: no intervention.

The three follow-up measures take place after the reduction program in week 6, 17 an 29. After the finalisation of the last follow-up, participants from the active comparator and waiting group get the chance to take part at the smoking reduction program at no charge.

Inclusion Criteria:

• 18-70 years
• Result Fagerström-Test >= 3
• Consumption of at least 10 Cig./day
• carbon monoxide >= 8 ppm
• Wish, to reduce smoking but no intention to stop smoking within the next 4 weeks
• Agreement, to resign to nicotine replacement therapy, other therapies for smoking reduction, e-cigarettes or non-smoking tobacco products during study time

Exclusion Criteria:

• severe psychiatric disorder
• severe neurologic disease
• alcohol, drug or medication abuse (acute or in anamnesis)
• severe cardiovascular disease
• severe cancer disease
• severe internal disease
• Consumption of psychopharmacological medication
• acute suicidal tendency
• pregnancy or lactation
• consumption of medication therapy for smoking reduction in the last 3 month