[Prevention of the onset of cigarette smoking in school: a critical approach to school-based studies].

This article explores the effectiveness of preventive interventions to smoking initiation in adolescents in school environment; it shows relevant aspects that account for the success or failure of those interventions and provides to professionals interested in the topic a selection of preventive strategies based on scientific evidence with the greatest impact when they are applied. It is concluded that the effectiveness of prevention programs on cigarette smoking initiation is partial and limited, because other interventions such as regulation of smoke-free areas, high price or control of sale and distribution are as important as the direct action on the new potential smokers.