One of the solutions implemented by schools for conducting value-based environmental education (EE) is outsourcing: allocating external environmental organizations that develop and conduct EE programmes. This study addressed such a programme--the Green Council Programme (GCP)--developed and implemented in schools by the Israeli Society for Protection of Nature. A pre-test/post-test design was used to investigate the influence of participation in the GCP on components of junior high-school students' environmental literacy. Conceptualizations of "environment", environmental attitudes and sense of ability to act on environmental issues were studied employing quantitative and qualitative tools. Contribution of the programme to the cognitive domain, in developing a systemic understanding of the environment, was limited. On the other hand, participating in this programme heightened students' sensitivity to human-environment interrelationships and developed a more ecological worldview. After the programme, students demonstrated greater perception of humans as part of the environment, an increased sensitivity to human impact on the environment and their value for non-human nature moved from an anthropocentric to a more ecocentric orientation. While students' internal locus-of-control increased, when environmental protection entailed personal economic trade-offs, their support was limited and remained unchanged. The article concludes with recommendations, based on the findings, regarding supplementing the school (science) curriculum with external EE enrichment programmes. (Contains 6 tables and 2 figures.)