BACKGROUND:To describe the effects of a Spanish smoking prevention programme in the context of an European project on regular smoking, in a sample of Barcelona adolescents.METHOD:A quasi-experimental design was conducted. An experimental group (EG) (1080 pupils) was exposed to programme and compared with a control group (CG) (872 students). The intervention included a school-based programme (16 sessions in 3 years), reinforcement of a smoke-free school policy, smoking cessation for teachers, brochures for parents and other community-based activities involving youth clubs and tobacco sales.RESULTS:At 12 months, 4.5% of boys and 5.6% of girls were new smokers in the EG versus 6.7% and 11.7% in the CG (P < 0.001). At 36 months, 18.6% of boys and 31.2% of girls in the EG were regular smokers versus 21.6% of boys and 38.3% of girls in the CG (P < 0.001). The main factors associated with progression to regular smoking at 36 months were to be girl, to attend to a public school and to belong to the CG.CONCLUSION:These results endorse the effectiveness of multi-modal smoking prevention programmes, which include strategies with adults who influence adolescents.