The present study aims at developing and evaluating a non-sequential smoking cessa-ti-on programme for in-patient rehabilitation centres. The new programme challenges the standard phased approach with the stages motivation, quit day, stabilisation. A prospective multi-centre study is conducted with quasi experimental control group design. The newly developed smoking cessation programme (intervention group, IG) is compared against the treatment-as-usual (control group, CG) of participating rehabilitation centres. Data from 850 smokers in 19 in-patient rehabilitation centres are analysed. The process evaluation of the non-sequential programme shows good acceptance among trainers and patients and easy implementation in the rehabilitation setting. Abstinence rates at the end of treatment are comparable for the IG (19.1%) and the CG (17.9%). The amount of cigarettes smoked among remaining smokers also reduced to a comparable degree in both groups. Patients in the IG showed significant improvement with regard to stages of change and self-efficacy. The non-sequential smoking cessation programme is accepted and can be implemented in an in-patient rehabilitation setting. With regard to major outcome criteria, the programme is comparable to treatment-as-usual. Secondary outcome criteria and satisfaction ratings favour the new programme. Due to a low-threshold access to smoking cessation, the non-sequential approach offers a structural advantage.