This research examines whether peer-led prevention programs are preferable to adult-led programs. Participants were 2,447 students in 94 classes, from 31 schools running drug prevention programs. The schools were divided into two groups according to the model they used in their program: fifteen schools used peer-led model, while sixteen used the adult-led model. A 46-item questionnaire was constructed in order to examine the students' perception of the programs. The results show that all the input measures (content, atmosphere, openness, discipline, facilitators' competence) and the outcome measures (satisfaction, knowledge, avoidance, curiosity, personal relationship) were perceived as more positive in the peer-led model. The differences were small, but significant. While the findings suggest that the peer-led model has a somewhat greater potential for primary prevention, the differences found do not enable us to state with certainty that this model is preferable for primary prevention purposes.