he need to evaluate a prevention programme developed under the paradigm of life skills, led to the design of an investigative strategy by means of which information was analysed on the performance of a sample of adolescents in a number of life skills (decision making, face-to-face relationships, communication, stress handling, self-esteem, peer pressure) and on drug use, before and after the application of the Trazando el Camino Programme on a Costa Rican student population in 2001. In order to achieve the proposed objective, a pretest-posttest design was used, within a quasi-experimental framework. A sample of 1897 young students completed a questionnaire in the pretest and 920 in the posttest. The results were interesting insofar as both the group where the programme was applied as well as the control group showed significant improvements in self-esteem, stress management, peer pressure and communication. This could be interpreted in respect of the typical evolution of adolescents during this period. It is also probable that the young people in both groups were exposed to additional preventive influences which were outside the knowledge and control of the researchers. It is considered that the evaluation period of the programme should be longer, with the aim of ascertaining its possible long-term effects, an objective of some importance as this programme is being implemented over the long term