As the results of some previous researches showed (Petrillo et al., 2004) the self-efficacy perceptions (Bandura, 1992) work into a more complex network of variables, which are prominent to health and act as the most important predictors both of the intention to carry out healthy behaviours and of their fulfilment (Schwarzer, 1992). Starting from a presupposition that the quality of life is both an individual and a social matter, this work was aimed at verifying the positive role of the personal and collective efficacy in the adolescence’s health promotion (2003 funds-Regional Law n. 5/02). For this end, we constructed some scales of measurement of personal self-efficacy with reference to different spheres of health’s protection and one scale of measurement of the school efficacy on health. Together with other tools, these scales were proposed to 1107 first and fourth class-students of Naples’s and Neapolitan area’s upper secondary schools. The results here illustrated are pertinent to: 1) the validation both of the new scales of school efficacy in the health promotion, and of the self-efficacy scale related to sexual behaviours, and alcohol and tobacco consumption; 2) the relations among the different perceptions of efficacy, the healthy behaviours and the well-being.