Abstract:We describe a student-centered, hands-on conservational program designed to alter adolescent environmental values and cognitive knowledge. The values (defined as sets of attitudes towards nature conservation) were measured using the 2-MEV scale (Two Major Environmental Values: Preservation, Utilization). Pre-existing knowledge levels and subsequent cognitive learning (short-, medium-and long-term) were scored on the basis of the three knowledge dimensions (system knowledge: Sys, action-related knowledge: Act and effectiveness knowledge: Eff ). Two hundred and seventy-one 6th to 8th graders, unaware of the testing schedules, completed our questionnaires two weeks before (T0), immediately after (T1), six weeks after (T2) and six months (T3) after participation in our nature and wildlife conservation program module. The linear mixed effects model (LMM) was used to analyze the relationships of cognitive knowledge with Preservation and Utilization: high Preservation scores predicted high overall pre-knowledge for all three knowledge types. High Utilization scores correlated with low pre-knowledge scores for all knowledge types. For Preservation, this positive relationship remained constant at all testing schedules. Utilization and knowledge acquisition correlated negatively in both the short (six weeks) and long terms (six months). Students scoring high on Preservation knew more, learned more, and forgot less in the short term than the low scorers. Students scoring high on Utilization briefly added cognitive knowledge immediately after the intervention, though this disappeared again in the short term. Educators are advised to build upon existing values and adjust their teaching on nature conservation issues accordingly.