The present study monitored a student-centred educational anti-smoking intervention with fifth graders by focusing on their cognitive achievement and intrinsic motivation. In order to assess the potential influence of the setting on self-directed learning, the intervention was conducted in two different learning environments: a classroom-based group in class at school; and an out-of-school group in an outreach setting at a youth camp. A control group didn't experience any specific intervention. Outcomes were assessed with an achievement test and the Intrinsic Motivation Inventory. Although in both learning settings similar cognitive levels were achieved, the out-of-school group showed a larger decrease in cognitive achievement and lower intrinsic motivation scores for interest and perceived choice. This empirical study adds new evidence to student-centred learning schemes in different learning environments, especially in an interdisciplinary context.