AIM: To assess the efficacy of an intervention based on the specific design and implementation of a mobile application (APP) in order to reduce the prevalence of smoking consumption among young people motivated 18 to 30 years METHODS: Cluster randomised clinical trial. Unit of randomization: Primary Health Care Centers (PHCC). Intention to treat analysis. STUDY POPULATION: Motivated young smokers of 10 or more cigarettes per day aged 18 to 30 years consulting for any reason to PHCC and who provided written informed consent to participate in the trial.